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Android学习笔记——Layout

tonglin0325

下面列举了Android中Layout，Table，Menu，Checkbox，Listview，Button，Bundle的基本使用和demo

1.Layout：该工程的功能是实现LinearLayout#

Android Layout有多种，比如：Layout，MixLayout，TableLayout等

以下的代码是MainActivity.java中的代码

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package com.example.linearlayout;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;


public class MainActivity extends Activity {

    private TextView firstText;
    private TextView secondText;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        firstText = (TextView)findViewById(R.id.firstText);
        secondText = (TextView)findViewById(R.id.secondText);
        
        firstText.setText(R.string.firstText);
        secondText.setText(R.string.secondText);
    }
}

 

以下的代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

<!-- 
         android:id            为控件制定相应的ID
        android:text        指定控件当中显示的文字
        android:gravity        指定控件的基本位置/居中居右等
        android:textSize    指定控件的基本位置/居中居右等 
        android:background    指定该控件所使用的背景色，RGB命名法
        android:width        指定控件的宽度
        android:height        指定控件的高度
        android:padding        指定控件的内边距
        android:weight        数字为相应的比例
        android:singleLine    设定true为同一行显示
         -->
        
  
   
    <TextView
        android:id="@+id/firstText"
        android:gravity="center_vertical"
        android:textSize="20pt"
        android:background="#0000ff"
        android:layout_width="fill_parent"
        android:layout_height="0.0dip"
        android:paddingLeft="10dip"
        android:paddingTop="20dip"
        android:paddingRight="30dip"
        android:paddingBottom="40dip"
        android:layout_weight="1"
        android:singleLine="true"
        />
    
    <TextView
        android:id="@+id/secondText"
        android:gravity="center_vertical"
        android:textSize="15pt"
        android:background="#00ff00"
        android:layout_width="fill_parent"
        android:layout_height="0.0dip"
        android:paddingLeft="10dip"
        android:paddingTop="20dip"
        android:paddingRight="30dip"
        android:paddingBottom="40dip"
        android:layout_weight="2"
        android:singleLine="true"
        />

</LinearLayout>

 

以下的代码是string.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">LinearLayout</string>
    <string name="hello_world">Hello world!</string>
    <string name="firstText">第一行</string>
    <string name="secondText">第二行</string>
</resources>

 

2.Layout：该工程的功能是实现LinearLayout+TableLayout#

以下代码是MainActivity.java中的代码

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package com.example.mixlayout;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

public class MainActivity extends Activity {

    private TextView firstText; 
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

 

以下代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:background="#aa0000"
            android:gravity="center_horizontal"
            android:text="red" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:background="#00aa00"
            android:gravity="center_horizontal"
            android:text="green" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:background="#0000aa"
            android:gravity="center_horizontal"
            android:text="blue" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <TableLayout 
            xmlns:android="http://schemas.android.com/apk/res/android" 
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:stretchColumns="1">
            <TableRow>

                <TextView
                    android:padding="3dip"
                    android:text="row1_column1" />

                <TextView
                    android:gravity="center_horizontal"
                    android:padding="3dip"
                    android:text="row1_column2" />

                <TextView
                    android:gravity="right"
                    android:padding="3dip"
                    android:text="row1_column3" />
            </TableRow>

            <TableRow>

                <TextView
                    android:padding="3dip"
                    android:text="row2_column1" />

                <TextView
                    android:gravity="center_horizontal"
                    android:padding="3dip"
                    android:text="row2_column2" />

                <TextView
                    android:gravity="right"
                    android:padding="3dip"
                    android:text="row2_column3" />
            </TableRow>
        </TableLayout>
    </LinearLayout>

</LinearLayout>

 

3.Table：该工程的功能是实现在一个activity中显示一个表格#

以下代码是MainActivity.java中的代码

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package com.example.tablelayout;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

 

以下的代码是activity_main.xml中的代码

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<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/TableLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:stretchColumns="1"
    tools:context="${relativePackage}.${activityClass}" >
    
    <!-- 由于fill_parent不能填满，所以stretchColumns指定列拉伸 -->
    
    <TableRow>
        <TextView
            android:text="@string/hello_world" 
            android:padding="3dip"
            android:background="#aa0000" />
        <TextView
            android:text="@string/hello_world" 
            android:padding="3dip"
            android:background="#00aa00"
            android:gravity="center_horizontal" />
        <TextView
            android:text="@string/hello_world" 
            android:padding="3dip"
            android:background="#0000aa"
            android:gravity="right" />
                     
    </TableRow>
        
    <TableRow>
        <TextView
            android:text="@string/hello_world" 
            android:padding="3dip" />
             
        <TextView
            android:text="@string/hello_world" 
            android:padding="3dip"
            android:gravity="right" />
                   
    </TableRow>

</TableLayout>

4.Menu：该工程的功能是实现两个数相乘，并在另外一个Activity中显示计算的结果#

以下的代码是MainActivity.java中的代码

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package com.example.menu;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;


public class MainActivity extends Activity {
    
    private EditText factorOne;
    private EditText factorTwo;
    private TextView symbol;
    private Button calculate;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        factorOne = (EditText)findViewById(R.id.factorOne);
        factorTwo = (EditText)findViewById(R.id.factorTwo);
        symbol = (TextView)findViewById(R.id.symbol);
        calculate = (Button)findViewById(R.id.calculate);
        
        //symbol.setText("乘以");
        //calculate.setText("计算");
        
        //为symbol和calculate设置显示的值
        symbol.setText(R.string.symbol);
        calculate.setText(R.string.calculate);
        //将监听器的对象绑定到按钮对象上面
        calculate.setOnClickListener(new CalculateListener());
    }
    
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // TODO Auto-generated method stub
        menu.add(0,1,1,R.string.exit);
        menu.add(0,2,2,R.string.about);
        return super.onCreateOptionsMenu(menu);
    }

    //当客户点击MENU按钮的时候，调用该方法
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // TODO Auto-generated method stub
        if(item.getItemId() == 1){
            finish();
        }
        return super.onOptionsItemSelected(item);
    }


    class CalculateListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            //取得两个EditText控件的值
            String factorOneStr = factorOne.getText().toString();
            String factorTwoStr = factorTwo.getText().toString();
            //将这两个值存放到Intent对象当中
            Intent intent = new Intent();
            intent.putExtra("one",factorOneStr);
            intent.putExtra("two",factorTwoStr);
            intent.setClass(MainActivity.this,ResultActivity.class );
            //使用这个Intent对象来启动ResultActivity
            MainActivity.this.startActivity(intent);
        }
        
        
    }
}

 

以下的代码是ResultActivity.java中的代码

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package com.example.menu;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class ResultActivity extends Activity{
    
    private TextView resultView;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_result);
        resultView = (TextView)findViewById(R.id.result);
        //得到Intent对象当中的值
        Intent intent = getIntent();
        String factorOneStr = intent.getStringExtra("one");
        String factorTwoStr = intent.getStringExtra("two");
        int factorOneInt = Integer.parseInt(factorOneStr);
        int factorTwoInt = Integer.parseInt(factorTwoStr);
        //计算两个值的积
        int result = factorOneInt * factorTwoInt;
        resultView.setText(result + "");
    }
}

 

以下的代码是activity_main.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <EditText
        android:id="@+id/factorOne"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
      />  
        
    <TextView
        android:id="@+id/symbol"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />

     <EditText
        android:id="@+id/factorTwo"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
      /> 
      
     <Button
         android:id="@+id/calculate"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         />
    
</LinearLayout>

 

以下的代码是activity_result.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

    <TextView
        android:id="@+id/result"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />
        

</LinearLayout>

 

以下的代码是string.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">menu</string>
    <string name="hello_world">Hello world!</string>
    <string name="resultLabel">result</string>
    <string name="symbol">乘法</string>
    <string name="calculate">计算</string>
    <string name="exit">退出</string>
    <string name="about">关于</string>
</resources>

 

以下的代码是AndroidManifest.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.menu"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name = ".ResultActivity">
        </activity>
    </application>

</manifest>

5.checkbox：该工程的功能实现在一个activity中显示一个单选框和一个多选框#

以下代码是MainActivity.java文件中的代码

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package com.example.checkbox;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class MainActivity extends Activity {
    //对控件对象进行声明
    private RadioGroup gendergroup = null;
    private RadioButton femaleButton = null;
    private RadioButton maleButton = null;
    private CheckBox swimBox = null;
    private CheckBox runBox = null;
    private CheckBox readBox = null;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //通过控件的ID来得到代表控件的对象
        gendergroup = (RadioGroup)findViewById(R.id.genderGroup);
        femaleButton = (RadioButton)findViewById(R.id.femaleButton);
        maleButton = (RadioButton)findViewById(R.id.maleButton);
        swimBox = (CheckBox)findViewById(R.id.swim);
        runBox = (CheckBox)findViewById(R.id.run);
        readBox = (CheckBox)findViewById(R.id.read);
        //设置监听器
        gendergroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                // TODO Auto-generated method stub
                if(femaleButton.getId() == checkedId){
                    System.out.println("female");
                    Toast.makeText(MainActivity.this, "female", Toast.LENGTH_SHORT).show();
                }
                else if(maleButton.getId() == checkedId)
                {
                    System.out.println("male");
                    Toast.makeText(MainActivity.this, "male", Toast.LENGTH_SHORT).show();
                }    
            }
        });
        //为多选按钮添加监听器
        swimBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                // TODO Auto-generated method stub
                if(isChecked)
                {
                    System.out.println("swim is checked");
                }
                else
                {
                    System.out.println("swim is unchecked");
                }
            }
        });
        runBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                // TODO Auto-generated method stub
                if(isChecked)
                {
                    System.out.println("run is checked");
                }
                else
                {
                    System.out.println("run is unchecked");
                }
            }
        });
        readBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                // TODO Auto-generated method stub
                if(isChecked)
                {
                    System.out.println("read is checked");
                }
                else
                {
                    System.out.println("read is unchecked");
                }
            }
        });
    }
}

 

以下代码是activity_main.xml文件中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <RadioGroup
        android:id="@+id/genderGroup"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        >
        
        <RadioButton
            android:id="@+id/femaleButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/female"
            />
    
        <RadioButton
            android:id="@+id/maleButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/male"
            />
    </RadioGroup>
    
    <CheckBox
        android:id="@+id/swim"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/swim"
        />
    <CheckBox
        android:id="@+id/run"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/run"
        />
    <CheckBox
        android:id="@+id/read"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/read"
        />
    
</LinearLayout>

 

以下代码是string.xml文件中的代码

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<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">CheckBox</string>
    <string name="hello_world">Hello world!</string>
    <string name="female">女</string>
    <string name="male">男</string>
    <string name="swim">游泳</string>
    <string name="run">跑步</string>
    <string name="read">读书</string>
</resources>

6.listview：该工程的功能是实现在一个activity中显示一个列表#

以下代码是MainActivity.java中的代码

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package com.example.listview;

import java.util.ArrayList;
import java.util.HashMap;


import android.app.ListActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.SimpleAdapter;

public class MainActivity extends ListActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        
        ArrayList<HashMap<String, String>> list = 
                new ArrayList<HashMap<String, String>>(); 
        HashMap<String, String> map1 = new HashMap<String,String>();
        HashMap<String, String> map2 = new HashMap<String,String>();
        HashMap<String, String> map3 = new HashMap<String,String>();
        
        map1.put("user_name","zhangsan");
        map1.put("user_ip","192.168.0.1");
        map2.put("user_name","lisi");
        map2.put("user_ip","192.168.0.2");
        map3.put("user_name","wangwu");
        map3.put("user_ip","192.168.0.3");
        
        list.add(map1);
        list.add(map2);
        list.add(map3);
        
        SimpleAdapter listAdapter = new SimpleAdapter(this, list, 
                R.layout.activity_user, new String[] {"user_name", "user_ip"},
                new int[] {R.id.user_name, R.id.user_ip});
        setListAdapter(listAdapter);
    }
}

 

以下的代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <LinearLayout
        android:id="@+id/listLinearLayout"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        >
        <ListView
            android:id="@id/android:list"
            android:scrollbars="vertical"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:drawSelectorOnTop="false"
            />
    </LinearLayout>

</LinearLayout>

 

以下代码是activity_user.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout2"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal"
    android:paddingLeft="10dip"
    android:paddingRight="10dip"
    android:paddingTop="1dip"
    android:paddingBottom="1dip"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/user_name"
        android:layout_width="180dip"
        android:layout_height="30dip"
        android:textSize="10pt"
        android:singleLine="true"
        />
    
    <TextView
        android:id="@+id/user_ip"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="right"
        android:textSize="10pt"
        />

</LinearLayout>&nbsp;

7.Button：工程的功能是实现在一个acticity上点击按钮，切换到另外一个activity#

以下代码为MainActivity.java中的代码

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package com.example.button_activity;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

    private Button myButton = null; 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myButton = (Button)findViewById(R.id.myButton);
        myButton.setOnClickListener(new MyButtonListener());  
    }
    
    class MyButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
        Intent intent = new Intent();
        intent.setClass(MainActivity.this, OtherActivity.class);
        MainActivity.this.startActivity(intent);
        }
        
        
    }
        
}

 

以下代码为OtherActivity.java中的代码

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package com.example.button_activity;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class OtherActivity extends Activity{

    private TextView myTextView = null; 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_other);
        myTextView = (TextView)findViewById(R.id.myTextView);
        myTextView.setText(R.string.other);
    }
    

}

 

以下代码为activity_main.xml中的代码

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<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <Button
        android:id="@+id/myButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        
        />

</RelativeLayout>

 

以下代码为activity_other.xml中的代码

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<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/myTextView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    

</RelativeLayout>

 

以下代码为string.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">button_activity</string>
    <string name="hello_world">Hello world!</string>
    <string name="other">OtherActivity</string>
</resources>

 

以下代码为AndroidManifest.xml中的代码 

注意修改package的名称

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<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.button_activity"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".OtherActivity"
            android:label="@string/other" >
        </activity>     
    </application>

</manifest>

 

如果不能运行请kill-adb和start-adb并重新启动eclipse

 

8.Button：该工程的功能是实现在activity中显示一个TextView和一个Button#

以下代码是MainActivity中的代码

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package com.example.button;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView myTextView = (TextView)findViewById(R.id.myTextView);
        Button myButton = (Button)findViewById(R.id.myButton);
        myTextView.setText("我的第一个TextView");
        myButton.setText("我的第一个Button");
        
    }
}

 

以下代码是activity_main中的代码

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<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/myTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <Button
        android:id="@+id/myButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />

</RelativeLayout>

 

该工程的功能是实现进度条的显示，按以下按钮进度条增加10%

 

以下代码是MainActivity.java中的代码

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package com.example.progressbar;

import android.app.Activity;

import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;

public class MainActivity extends Activity {
    
    //申明限量
    private ProgressBar firstBar = null;
    private ProgressBar secondBar = null;
    private Button myButton = null;
    private int i = 0;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //根据控件的ID来取得代表控件的对象
        firstBar = (ProgressBar)findViewById(R.id.firstBar);
        secondBar = (ProgressBar)findViewById(R.id.secondBar);
        myButton = (Button)findViewById(R.id.myButton);
        myButton.setOnClickListener(new ButtonListener());
        System.out.print(firstBar.getMax());
    }
    
    class ButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if(i == 0)
            {    
                //设置进度条处于可见的状态
                firstBar.setVisibility(View.VISIBLE);
                secondBar.setVisibility(View.VISIBLE);
            }
            else if(i < firstBar.getMax())
            {    
                //设置主进度条的当前值
                firstBar.setProgress(i);
                //设置第二进度条的当前值
                firstBar.setSecondaryProgress(i + 10);
                //因为默认的进度条无法显示进行的状态
                //secondBar.setProgress(i);
            }
            else
            {    
                //设置进度条处于不可见状态
                firstBar.setVisibility(View.GONE);
                secondBar.setVisibility(View.GONE);
            }
            i = i + 10;
        }

    }
}

 

以下代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <ProgressBar
        android:id="@+id/firstBar"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:visibility="gone"
        />
    
    <ProgressBar
        android:id="@+id/secondBar"
        style="?android:attr/progressBarStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"
        android:max="200"
        />

    <Button
        android:id="@+id/myButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="begin"
        />
    
    
</LinearLayout>

 

9.Bundle：该工程的功能是实现不同线程之间数据的传递#

以下代码是MainActivity.java中的代码

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package com.example.bundle;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //打印了当前线程的ID
        System.out.println("Activity-->"  + Thread.currentThread().getId());
        //生成一个HandleThread对象，实现了使用Looper来处理消息队列的功能，这个类由android程序框架提供
        HandlerThread handlerThread = new HandlerThread("handler_thread");
        //在使用HandlerThread的getLooper（）方法之前，必须先调用该类的start（）
        handlerThread.start();
        MyHandler myHandler = new MyHandler(handlerThread.getLooper());
        Message msg = myHandler.obtainMessage();
        //msg.obj="abc";
        //将msg发送到目标对象，所谓的目标对象，就是生成该msg对象的handler对象
        Bundle b = new Bundle();
        b.putInt("age", 20);
        b.putString("name", "John");
        msg.setData(b);
        msg.sendToTarget();
    }
    
    class MyHandler extends Handler{
        public MyHandler(){
            
        }
        public MyHandler(Looper looper){
            //super调用父类
            super(looper);
        }
        public void handleMessage(Message msg){
            //String s = (String)msg.obj;
            Bundle b = msg.getData();
            int age = b.getInt("age");
            String name = b.getString("name");
            System.out.println("age is " + age +", name is " + name);
            System.out.println("Handler-->" + Thread.currentThread().getId());
            System.out.println("handlerMessage");
        }
    }
}


以下代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</LinearLayout>

 

10.ProcessBar：该工程的功能是实现点击按钮进度条按10%递增，使用的方式是Handler#

以下的代码是MainActivity.java中的代码

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package com.example.progressbarhandler;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;


public class MainActivity extends Activity {
    //申明变量
    ProgressBar bar = null;
    Button startButton = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //根据空间的ID得到代表控件的对象，并未按钮去设置监听器
        bar = (ProgressBar)findViewById(R.id.bar);
        startButton = (Button)findViewById(R.id.startButton);
        startButton.setOnClickListener(new ButtonListener());
    }
    
    class ButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            bar.setVisibility(View.VISIBLE);
            updateBarHandler.post(updateThread);
        }
    }
    //使用匿名内部类来复写Handler当中的handMessage方法
    Handler updateBarHandler = new Handler(){
        public void handleMessage(Message msg){
            bar.setProgress(msg.arg1);
            //线程队列
            updateBarHandler.post(updateThread);
        }    
    };
    //线程类，该类使用匿名内部类的方式进行声明
    Runnable updateThread = new Runnable(){
        int i = 0;
        public void run(){
            System.out.println("Begin Thread");
            i = i + 10;
            //得到一个消息对象，message类是由android操作系统提供
            Message msg = updateBarHandler.obtainMessage();
            //将msg对象的arg1参数的值设置为i，用arg1和arg2这两个成员传递消息
            msg.arg1 = i;
            try{
                //设置当前显示睡眠1秒
                Thread.sleep(1000);
            }
            catch (InterruptedException e){
                e.printStackTrace();
            }
            //将msg对象加入到消息队列当中
            updateBarHandler.sendMessage(msg);
            if(i == 100){
                //如果当i的值为100时，就将线程对象从handle当中移除
                updateBarHandler.removeCallbacks(updateThread);
            }
        }
    };
}

 

以下的代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <ProgressBar
        android:id="@+id/bar"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:visibility="gone"
        />

    <Button
        android:id="@+id/startButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="start"
        />
</LinearLayout>

 

11.Handler：线程管理#

步骤：

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1. 申请一个Handler对象
Handler handler = new Handler();

2. 创建一个线程
{继承Thread类或者实现Runnable这个接口}
使用Runnable创建一个内部匿名类对象updateThread（要复写run方法）

3. 使用handler的post方法将线程加入到线程队列中
handler.post(updateThread);

4. 使用handler的removeCallbacks方法移出updateThread线程
注意：如果线程从线程队列中出来被执行后，则队列中就不在有线程
因此如果线程在被执行后没有方法将其再次加入到队列中，则无需使用removeCallbacks

线程走出线程队列有两种情况：
一种是被执行，此时要执行run方法
一种是使用removeCallbacks方法，此时线程不被执行，因此不调用run

5. 使用handler的postDelayed方法延时将线程加入到队列中
handler.postDelayed(updateThread,3000)

 

以下代码是MainActivity.java中的代码

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package com.example.handler;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    //声明两个按钮控件
    private Button StartButton = null;
    private Button EndButton = null;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //根据控件的ID得到代表控件的对象，并为这两个按钮设置相应的监听器
        StartButton = (Button)findViewById(R.id.StartButton);
        StartButton.setOnClickListener(new  StartButotnListener());
        EndButton = (Button)findViewById(R.id.EndButton);
        EndButton.setOnClickListener(new  EndButtonListener());
    }
    
    class StartButotnListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            handler.post(updateThread);
        }
    }
    
    class EndButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            handler.removeCallbacks(updateThread);
        }
    }
    //创建一个Handler对象
    Handler handler = new Handler();
    //将要执行的操作下载线程对象的run方法当中
    Runnable updateThread = new Runnable(){
        
        public void run(){
            System.out.println("UpdateThread");
            //在run方法内部，执行postDelayed或者是post方法
            handler.postDelayed(updateThread,3000);
        }
    };
}

 

以下代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    
    
    <Button
        android:id="@+id/StartButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Start"
        />
    
    <Button
        android:id="@+id/EndButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="End"
        />

</LinearLayout>

 

以下代码是MainActivity.java中的代码

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package com.example.handlertest;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;


public class MainActivity extends Activity {
    
    private Handler handler = new Handler();
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        setContentView(R.layout.activity_main);
        handler.post(r);
        //Thread t = new Thread(r);
        //t.start();
        System.out.println("activity--->"+ Thread.currentThread().getId());
        System.out.println("activityname--->"+ Thread.currentThread().getName());
    }
    
    Runnable r = new Runnable(){
        public void run() {
            System.out.println("handler--->"+ Thread.currentThread().getId());
            System.out.println("handlername--->"+ Thread.currentThread().getName());
            try{
                Thread.sleep(10000);
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
        }
    };
}

 

以下代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</LinearLayout>

 

12.Download：该工程的功能是实现Download#

1.该工程的功能是实现从网上的链接下载一个lrc文件和一个mp3文件

以下代码是MainActivity.java中的代码

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package com.example.download;


import com.example.utils.HttpDownloader;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    private Button downloadTxtButton;
    private Button downloadMp3Button;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        downloadTxtButton = (Button)findViewById(R.id.downloadTxt);
        downloadTxtButton.setOnClickListener(new DownloadTxtListener());
        downloadMp3Button = (Button)findViewById(R.id.downloadMp3);
        downloadMp3Button.setOnClickListener(new DownloadMp3Listener());
    }
    
    class DownloadTxtListener implements OnClickListener{
        public void onClick(View v) {
        HttpDownloader httpDownloader = new HttpDownloader();
        int lrc = httpDownloader.downFile("http://play.baidu.com/data2/lrc/121017633/121017633.lrc", "voa/", "1201250291414036861128.lrc");
        System.out.println(lrc);
        } 
    }
    
    class DownloadMp3Listener implements OnClickListener{
        public void onClick(View v) {
        // TODO Auto-generated method stub
        HttpDownloader httpDownloader = new HttpDownloader();
        int result = httpDownloader.downFile("http://cdn.y.baidu.com/yinyueren/532bfdb43a336a584533ff61a7289503.mp3", "voa/", "江南.mp3");
        System.out.println(result);
        }
    }
    
}

 

以下代码是FileUtils.java中的代码

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package com.example.utils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.os.Environment;

public class FileUtils {
    private String SDPATH;
    public String getSDPATH() {
    return SDPATH;
    }
    
    public FileUtils() {
     //得到当前外部存储设备的目录
     // /SDCARD
     SDPATH = Environment.getExternalStorageDirectory() + "/";
    }
    
    /**
     * 在SD卡上创建文件
     * 
     * @throws IOException
     */
    public File creatSDFile(String fileName) throws IOException {
        File file = new File(SDPATH + fileName);
        file.createNewFile();
        return file;
    }
 
    /**
     * 在SD卡上创建目录
     * 
     * @param dirName
     */
    public File creatSDDir(String dirName) {
        File dir = new File(SDPATH + dirName);
        dir.mkdirs();
        return dir;
    }
    
    /**
     * 判断SD卡上的文件夹是否存在
     */
    public boolean isFileExist(String fileName){
        File file = new File(SDPATH + fileName);
        return file.exists();
    }
 
    /**
     * 将一个InputStream里面的数据写入到SD卡中
     */
    public File write2SDFromInput(String path,String fileName,InputStream input){
        File file = null;
        OutputStream output = null;
        try{
            creatSDDir(path);
            file = creatSDFile(path + fileName);
            output = new FileOutputStream(file);
            byte buffer [] = new byte[4 * 1024];
            int len=-1;
            while((len=input.read(buffer)) != -1){
                //在这里使用另一个重载，防止流写入的问题.
                output.write(buffer,0,len);
            }
            output.flush();
        }
        catch(Exception e){
            e.printStackTrace();
        }
        finally{
                try{
                    output.close();
                }    
                catch(Exception e){
                    e.printStackTrace();
                }
        }
        return file;
    }
}

 

以下代码是HttpDownloader.java中的代码

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package com.example.utils;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class HttpDownloader {
    private URL url = null;
    /**
     * 根据URL下载文件，前提是这个文件当中的内容是文本，函数的返回值就是文件当中的内容
     * 1.创建一个URL对象
     * 2.通过URL对象，创建一个HttpURLConnection对象
     * 3.得到InputStram
     * 4.从InputStream当中读取数据
     * @param urlStr
     * @return
     */
    
    public String download(String urlStr) {
        StringBuffer sb = new StringBuffer();
        String line = null;
        BufferedReader buffer = null;
        try {
            // 创建一个URL对象
            url = new URL(urlStr);
            // 创建一个Http连接
            HttpURLConnection urlConn = (HttpURLConnection) url
                    .openConnection();
            // 使用IO流读取数据
            buffer = new BufferedReader(new InputStreamReader(urlConn
                    .getInputStream()));
            while ((line = buffer.readLine()) != null) {
                sb.append(line);
            }
        } 
        catch (Exception e) {
            e.printStackTrace();
        } 
        finally {
            try {
                buffer.close();
            } 
            catch (Exception e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
 
    /**
     * 该函数返回整形 -1：代表下载文件出错 0：代表下载文件成功 1：代表文件已经存在
     */
    public int downFile(String urlStr, String path, String fileName) {
        InputStream inputStream = null;
        try {
            FileUtils fileUtils = new FileUtils();
   
            if (fileUtils.isFileExist(path + fileName)) {
                return 1;
            } 
            else {
                inputStream = getInputStreamFromUrl(urlStr);
                File resultFile = fileUtils.write2SDFromInput(path,fileName, inputStream);
                if (resultFile == null) {
                    return -1;
                }
            }
        } 
        catch (Exception e) {
            e.printStackTrace();
            return -1;
        } 
        finally {
            try {
                inputStream.close();
            } 
            catch (Exception e) {
                e.printStackTrace();
            }
        }
        return 0;
    }
 
    /**
     * 根据URL得到输入流
     * 
     * @param urlStr
     * @return
     * @throws MalformedURLException
     * @throws IOException
     */
    public InputStream getInputStreamFromUrl(String urlStr)
        throws MalformedURLException, IOException {
        url = new URL(urlStr);
        HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
        InputStream inputStream = urlConn.getInputStream();
        return inputStream;
    }
}

 

以下代码是activity_main.xml中的代码

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <Button
        android:id="@+id/downloadTxt"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="downloadTxt"
        />
    
    <Button
        android:id="@+id/downloadMp3"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="downloadMp3"
        />

</LinearLayout>

 

以下代码是AndroidManifest.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.download"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-sdk android:minSdkVersion="8" />  
    <!-- 访问网络和操作SD卡 加入的两个权限配置-->  
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    
</manifest>

 

2.该工程实现下载一个xml文件，并解析

转自http://blog.csdn.net/sam_zhang1984

      XML 解析主要需要进行下列步骤：

      1.        创建事件处理程序

      2.        创建 SAX 解析器

      3.        将事件处理程序分配给解析器

      4.        对文档进行解析，将每个事件发送给处理程序。

 

以下的代码是MainActivity.java中的代码

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package com.example.xml;

import java.io.StringReader;

import javax.xml.parsers.SAXParserFactory;

import com.example.utils.HttpDownloader;

import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    private Button parseButton ;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        parseButton = (Button)findViewById(R.id.parseButton);
        parseButton.setOnClickListener(new ParseButtonListener());
    }
    
    class ParseButtonListener implements OnClickListener{

        public void onClick(View v) {
            HttpDownloader hd = new HttpDownloader();
            String resultStr = hd.download("http://192.168.1.107:8081/voa1500/test.xml");
            System.out.println(resultStr);
            try{
                //创建一个SAXParserFactory
                SAXParserFactory factory = SAXParserFactory.newInstance();
                XMLReader reader = factory.newSAXParser().getXMLReader();
                //为XMLReader设置内容处理器
                reader.setContentHandler(new MyContentHandler());
                //开始解析文件
                reader.parse(new InputSource(new StringReader(resultStr)));
            }
            catch(Exception e){
                e.printStackTrace();
            }
        }
        
    }
}

 

以下的代码是MyContentHandler.java中的代码

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package com.example.xml;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class MyContentHandler extends DefaultHandler {
    String hisname, address, money, sex, status;
    String tagName;

    public void startDocument() throws SAXException {
        System.out.println("````````begin````````");
    }

    public void endDocument() throws SAXException {
        System.out.println("````````end````````");
    }

    public void startElement(String namespaceURI, String localName,
            String qName, Attributes attr) throws SAXException {
        tagName = localName;
        if (localName.equals("worker")) {
            //获取标签的全部属性
            for (int i = 0; i < attr.getLength(); i++) {
                System.out.println(attr.getLocalName(i) + "=" + attr.getValue(i));
            }
        }
    }

    public void endElement(String namespaceURI, String localName, String qName)
            throws SAXException {
        //在workr标签解析完之后，会打印出所有得到的数据
        tagName = "";
        if (localName.equals("worker")) {
            this.printout();
        }
    }
    public void characters(char[] ch, int start, int length)
            throws SAXException {
        if (tagName.equals("name"))
            hisname = new String(ch, start, length);
        else if (tagName.equals("sex"))
            sex = new String(ch, start, length);
        else if (tagName.equals("status"))
            status = new String(ch, start, length);
        else if (tagName.equals("address"))
            address = new String(ch, start, length);
        else if (tagName.equals("money"))
            money = new String(ch, start, length);
    }

    private void printout() {
        System.out.print("name: ");
        System.out.println(hisname);
        System.out.print("sex: ");
        System.out.println(sex);
        System.out.print("status: ");
        System.out.println(status);
        System.out.print("address: ");
        System.out.println(address);
        System.out.print("money: ");
        System.out.println(money);
        System.out.println();
    }

}

 

以下的代码是FileUtils.java中的代码

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package com.example.utils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.os.Environment;

public class FileUtils {
    private String SDPATH;
    public String getSDPATH() {
    return SDPATH;
    }
    
    public FileUtils() {
     //得到当前外部存储设备的目录
     // /SDCARD
     SDPATH = Environment.getExternalStorageDirectory() + "/";
    }
    
    /**
     * 在SD卡上创建文件
     * 
     * @throws IOException
     */
    public File creatSDFile(String fileName) throws IOException {
        File file = new File(SDPATH + fileName);
        file.createNewFile();
        return file;
    }
 
    /**
     * 在SD卡上创建目录
     * 
     * @param dirName
     */
    public File creatSDDir(String dirName) {
        File dir = new File(SDPATH + dirName);
        dir.mkdirs();
        return dir;
    }
    
    /**
     * 判断SD卡上的文件夹是否存在
     */
    public boolean isFileExist(String fileName){
        File file = new File(SDPATH + fileName);
        return file.exists();
    }
 
    /**
     * 将一个InputStream里面的数据写入到SD卡中
     */
    public File write2SDFromInput(String path,String fileName,InputStream input){
        File file = null;
        OutputStream output = null;
        try{
            creatSDDir(path);
            file = creatSDFile(path + fileName);
            output = new FileOutputStream(file);
            byte buffer [] = new byte[4 * 1024];
            int len=-1;
            while((len=input.read(buffer)) != -1){
                //在这里使用另一个重载，防止流写入的问题.
                output.write(buffer,0,len);
            }
            output.flush();
        }
        catch(Exception e){
            e.printStackTrace();
        }
        finally{
                try{
                    output.close();
                }    
                catch(Exception e){
                    e.printStackTrace();
                }
        }
        return file;
    }
}

 

以下的代码是HttpDownloader.java中的代码

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package com.example.utils;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class HttpDownloader {
    private URL url = null;
    /**
     * 根据URL下载文件，前提是这个文件当中的内容是文本，函数的返回值就是文件当中的内容
     * 1.创建一个URL对象
     * 2.通过URL对象，创建一个HttpURLConnection对象
     * 3.得到InputStram
     * 4.从InputStream当中读取数据
     * @param urlStr
     * @return
     */
    
    public String download(String urlStr) {
        StringBuffer sb = new StringBuffer();
        String line = null;
        BufferedReader buffer = null;
        try {
            // 创建一个URL对象
            url = new URL(urlStr);
            // 创建一个Http连接
            HttpURLConnection urlConn = (HttpURLConnection) url
                    .openConnection();
            // 使用IO流读取数据
            buffer = new BufferedReader(new InputStreamReader(urlConn
                    .getInputStream()));
            while ((line = buffer.readLine()) != null) {
                sb.append(line);
            }
        } 
        catch (Exception e) {
            e.printStackTrace();
        } 
        finally {
            try {
                buffer.close();
            } 
            catch (Exception e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
 
    /**
     * 该函数返回整形 -1：代表下载文件出错 0：代表下载文件成功 1：代表文件已经存在
     */
    public int downFile(String urlStr, String path, String fileName) {
        InputStream inputStream = null;
        try {
            FileUtils fileUtils = new FileUtils();
   
            if (fileUtils.isFileExist(path + fileName)) {
                return 1;
            } 
            else {
                inputStream = getInputStreamFromUrl(urlStr);
                File resultFile = fileUtils.write2SDFromInput(path,fileName, inputStream);
                if (resultFile == null) {
                    return -1;
                }
            }
        } 
        catch (Exception e) {
            e.printStackTrace();
            return -1;
        } 
        finally {
            try {
                inputStream.close();
            } 
            catch (Exception e) {
                e.printStackTrace();
            }
        }
        return 0;
    }
 
    /**
     * 根据URL得到输入流
     * 
     * @param urlStr
     * @return
     * @throws MalformedURLException
     * @throws IOException
     */
    public InputStream getInputStreamFromUrl(String urlStr)
        throws MalformedURLException, IOException {
        url = new URL(urlStr);
        HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
        InputStream inputStream = urlConn.getInputStream();
        return inputStream;
    }
}

 

以下的代码是activity_main.xml中的代码

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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
         android:id="@+id/parseButton"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="开始解析XML"/>
</LinearLayout>

 

tonglin0325

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