android学习笔记10（activity的死亡，菜单，及对话框）

activity的死亡:在跳转时，加个finish()即可

对话框需要在manifest中配置，我找的好苦

First.java

package tk.myactivity06;

import java.security.PublicKey;

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

public class First extends Activity {

    private Button myButton=null; 
    
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.first); 
        myButton=(Button)findViewById(R.id.first); 
        myButton.setText(R.string.first); 
        myButton.setOnClickListener(new FirstButtonListener()); 
        
    } 
    class FirstButtonListener implements OnClickListener{ 
        
        @Override 
        public void onClick(View v){ 
            Intent intent=new Intent(); 
            intent.setClass(First.this,Second.class ); 
            First.this.startActivity(intent); 
                   finish(); 
        } 
    } 
  //添加菜单 
    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
        menu.add(0, 1, 1, R.string.exit ); 
           menu.add(0, 2, 2, R.string.about); 
        getMenuInflater().inflate(R.menu.first, menu); 
        return true; 
    } 
  
  //菜单项处理 
    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
           if(item.getItemId() == 1){ 
                 finish(); 
          }else if(item.getItemId()==2){ 
            Intent intent=new Intent(); 
              intent.setClass(First.this,About.class ); 
              First.this.startActivity(intent); 
          } 
           return super .onOptionsItemSelected(item); 
   } 
}

first.xml

<?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" 
> 
<Button 
android:id="@ id/first" 
android:layout_width="fill_parent" 
android:layout_height="wrap_content" 
/> 

</LinearLayout>

Second.java

package tk.myactivity06;

import tk.myactivity06.First.FirstButtonListener; 
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 Second extends Activity{ 
    private Button myButton=null; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.second); 
        myButton=(Button)findViewById(R.id.second); 
        myButton.setText(R.string.second); 
        myButton.setOnClickListener(new SecondButtonListener()); 
    } 
    class SecondButtonListener implements OnClickListener{ 
        
        @Override 
        public void onClick(View v){ 
            Intent intent=new Intent(); 
            intent.setClass(Second.this,Three.class ); 
            Second.this.startActivity(intent); 
            finish(); 
        } 
    }

    //添加菜单 
    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
        menu.add(0, 1, 1, R.string.exit ); 
           menu.add(0, 2, 2, R.string.about); 
        getMenuInflater().inflate(R.menu.first, menu); 
        return true; 
    } 
  //菜单项处理 
    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
           if(item.getItemId() == 1){ 
                 finish(); 
          } 
           return super .onOptionsItemSelected(item); 
   }

}

second.xml

<?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" 
    > 
     <Button 
         android:id="@ id/second" 
         android:layout_width="fill_parent" 
         android:layout_height="wrap_content" 
         /> 
</LinearLayout>

Three.java

package tk.myactivity06;

import tk.myactivity06.Second.SecondButtonListener; 
import android.app.Activity; 
import android.content.Intent; 
import android.net.Uri; 
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 Three extends Activity{ 
    private Button myButton=null; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.three); 
        myButton=(Button)findViewById(R.id.three); 
        myButton.setText(R.string.three); 
        myButton.setOnClickListener(new ThreeButtonListener()); 
    } 
    class ThreeButtonListener implements OnClickListener{ 
        
        @Override 
        public void onClick(View v){ 
            Intent intent=new Intent(); 
            intent.setClass(Three.this,First.class ); 
            Three.this.startActivity(intent); 
            finish(); 
                   
        } 
    } 
    //添加菜单 
    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
        menu.add(0, 1, 1, R.string.exit ); 
           menu.add(0, 2, 2, R.string.about); 
        getMenuInflater().inflate(R.menu.first, menu); 
        return true; 
    } 
  //菜单项处理 
    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
           if(item.getItemId() == 1){ 
                 finish(); 
          } 
           return super .onOptionsItemSelected(item); 
   } 
}

three.xml

<?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" 
    > 
     <Button 
         android:id="@ id/three" 
         android:layout_width="fill_parent" 
         android:layout_height="wrap_content" 
         ></Button> 
</LinearLayout>

About.java

package tk.myactivity06;

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

public class About extends Activity{ 
    private Button myButton=null; 
    
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.about); 
        myButton=(Button)findViewById(R.id.about); 
        myButton.setText(R.string.about); 
        myButton.setOnClickListener(new AboutButtonListener()); 
    } 
    class AboutButtonListener implements OnClickListener{ 
        
        @Override 
        public void onClick(View v){ 
                   finish(); 
        } 
    } 
}

about.xml

<?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" 
    > 
     <Button 
         android:id="@ id/about" 
         android:layout_width="fill_parent" 
         android:layout_height="wrap_content" 
         /> 
    
</LinearLayout>

  
manifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="tk.myactivity06" 
    android:versionCode="1" 
    android:versionName="1.0" >

    <uses-sdk 
        android:minSdkVersion="8" 
        android:targetSdkVersion="15" />

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

                <category android:name="android.intent.category.LAUNCHER" /> 
            </intent-filter> 
        </activity> 
          <activity 
            android:name=".Second" 
            android:label="@string/second" 
            > 
       
        </activity> 
          <activity 
            android:name=".About" 
            android:label="@string/about" 
            android:theme="@android:style/Theme.Dialog" 
            > 
       
        </activity> 
          <activity 
            android:name=".Three" 
            android:label="@string/three" 
            > 
       
        </activity> 
        
    </application>

</manifest>