系出名门Android(4) - 活动(Activity), 服务(Service), 广播(Broadcast), 广播接收器(BroadcastReceiver)

package com.webabcd.activity; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

public  class Main  extends Activity { 
         
        TextView txt; 
         
         /** Called when the activity is first created. */ 
        @Override 
         public  void onCreate(Bundle savedInstanceState) { 
                 super.onCreate(savedInstanceState); 
                 this.setContentView(R.layout.main); 

                txt = (TextView)  this.findViewById(R.id.txt); 
                txt.setText( "Activity 1"); 

                Button btn = (Button)  this.findViewById(R.id.btn); 
                btn.setText( "启动另一个Activity"); 
                btn.setOnClickListener( new Button.OnClickListener() { 
                        @Override 
                         public  void onClick(View v) { 
                                 
                                 // 实例化 Intent，指定需要启动的 Activity 
                                Intent intent =  new Intent(); 
                                intent.setClass(Main. this, MyActivity. class); 

                                 // 实例化 Bundle，设置需要传递的参数 
                                Bundle bundle =  new Bundle(); 
                                bundle.putString( "name",  "webabcd"); 
                                bundle.putDouble( "salary", 100.13); 

                                 // 将需要传递的参数赋值给 Intent 对象 
                                intent.putExtras(bundle); 

                                 // startActivity(intent); // 启动指定的 Intent（不等待返回结果） 
                                 // Main.this.finish(); 
                                 
                                 // 启动指定的 Intent，并等待返回结果 
                                 // 其中第二个参数如果大于等于零，则返回结果时会回调 onActivityResult() 方法 
                                startActivityForResult(intent, 0); 
                        } 
                }); 
                 
                Log.d( "MyDebug",  "onCreate"); 
        } 
         
         // 被启动的 Activity 返回结果时的回调函数 
        @Override 
         protected  void onActivityResult( int requestCode,  int resultCode, Intent data) { 
                 if (resultCode == Activity.RESULT_OK){ 
                        Bundle bundle = data.getExtras(); 
                         
                        String name = bundle.getString( "name"); 
                         double salary = bundle.getDouble( "salary"); 
                         
                        txt.setText( "Activity 1" +  "\n名字：" + name +  "\n薪水：" + String.valueOf(salary)); 
                } 
        } 

        @Override 
         protected  void onStart() { 
                 // TODO Auto-generated method stub 
                 super.onStart(); 
                 
                Log.d( "MyDebug",  "onStart"); 
        } 

        @Override 
         protected  void onStop() { 
                 // TODO Auto-generated method stub 
                 super.onStop(); 
                 
                Log.d( "MyDebug",  "onStop"); 
        } 

        @Override 
         protected  void onRestart() { 
                 // TODO Auto-generated method stub 
                 super.onRestart(); 
                 
                Log.d( "MyDebug",  "onRestart"); 
        } 
         
        @Override 
         protected  void onPause() { 
                 // TODO Auto-generated method stub 
                 super.onPause(); 
                 
                Log.d( "MyDebug",  "onPause"); 
        } 

        @Override 
         protected  void onResume() { 
                 // TODO Auto-generated method stub 
                 super.onResume(); 
                 
                Log.d( "MyDebug",  "onResume"); 
        } 
         
        @Override 
         protected  void onDestroy() { 
                 // TODO Auto-generated method stub 
                 super.onDestroy(); 
                 
                Log.d( "MyDebug",  "onDestroy"); 
        } 
}

package com.webabcd.activity; 

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

// 被另一个 Activity 所启动的 Activity 
public  class MyActivity  extends Activity { 
         
        Intent intent; 
         
         /** Called when the activity is first created. */ 
        @Override 
         public  void onCreate(Bundle savedInstanceState) { 
                 super.onCreate(savedInstanceState); 
                 this.setContentView(R.layout.main2); 

                 // 获取启动者传递过来的参数 
                intent =  this.getIntent(); 
                Bundle bundle = intent.getExtras();                 
                String name = bundle.getString( "name"); 
                 double salary = bundle.getDouble( "salary"); 
                 
                TextView txt = (TextView)  this.findViewById(R.id.txt); 
                txt.setText( "Activity 2" +  "\n名字：" + name +  "\n薪水：" + String.valueOf(salary)); 

                Button btn = (Button)  this.findViewById(R.id.btn); 
                btn.setText( "返回前一个Activity"); 
                btn.setOnClickListener( new Button.OnClickListener() { 
                         public  void onClick(View v) { 
                                 // 返回参数给启动者 
                                MyActivity. this.setResult(Activity.RESULT_OK, intent); 
                                MyActivity. this.finish(); 
                        } 
                }); 
        } 
}

<? xml  version ="1.0"  encoding ="utf-8" ?> 
< manifest  xmlns:android ="http://schemas.android.com/apk/res/android" 
         package ="com.webabcd.activity"  android:versionCode ="1" 
         android:versionName ="1.0" > 
         < application  android:icon ="@drawable/icon"  android:label ="@string/app_name" > 
                 < activity  android:name =".Main"  android:label ="@string/app_name" > 
                         < intent-filter > 
                                 < action  android:name ="android.intent.action.MAIN"  /> 
                                 < category  android:name ="android.intent.category.LAUNCHER"  /> 
                         </ intent-filter > 
                 </ activity > 
                <!--  
                        如果有需要用到的 Activity ，则都要在这里做相应的配置 
                --> 
                 < activity  android:name =".MyActivity"  android:label ="Activity 2"  /> 
         </ application > 
         < uses-sdk  android:minSdkVersion ="3"  /> 
</ manifest >

package com.webabcd.service; 

import android.app.Activity; 
import android.content.BroadcastReceiver; 
import android.content.ComponentName; 
import android.content.Context; 
import android.content.Intent; 
import android.content.IntentFilter; 
import android.content.ServiceConnection; 
import android.os.Bundle; 
import android.os.IBinder; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.TextView; 

/* 
* startService() 和 bindService() 的区别    
* startService() - 正常理解就好 
* bindService() - 使当前上下文对象（本例中就是 Activity）通过一个 ServiceConnection 对象邦定到指定的 Service 。这样，如果上下文对象销毁了的话，那么其对应的 Service 也会被销毁 
*/ 
public  class Main  extends Activity  implements OnClickListener { 

         private TextView txtMsg; 
         
        @Override 
         public  void onCreate(Bundle savedInstanceState) { 
                 super.onCreate(savedInstanceState); 
                setContentView(R.layout.main); 

                setTitle( "android 之 service"); 

                 this.findViewById(R.id.btnStart).setOnClickListener( this); 
                 this.findViewById(R.id.btnStop).setOnClickListener( this); 
                 this.findViewById(R.id.btnBind).setOnClickListener( this); 
                 this.findViewById(R.id.btnUnbind).setOnClickListener( this); 
                 
                txtMsg = (TextView) this.findViewById(R.id.txtMsg); 
                 
                 // 实例化自定义的 BroadcastReceiver 
                receiver =  new UpdateReceiver(); 
                IntentFilter filter =  new IntentFilter(); 
                 // 为 BroadcastReceiver 指定 action ，使之用于接收同 action 的广播 
                filter.addAction( "com.webabcd.service.msg"); 
                 
                 // 以编程方式注册    BroadcastReceiver 。配置方式注册 BroadcastReceiver 的例子见 AndroidManifest.xml 文件 
                 // 一般在 OnStart 时注册，在 OnStop 时取消注册 
                 this.registerReceiver(receiver, filter); 
                 // this.unregisterReceiver(receiver); 
                 
        } 

        @Override 
         public  void onClick(View v) { 
                Intent intent =  new Intent(Main. this, MyService. class); 
                 switch (v.getId()) { 
                 case R.id.btnStart: 
                         this.startService(intent); 
                         break; 
                 case R.id.btnStop: 
                         this.stopService(intent); 
                         break; 
                 case R.id.btnBind: 
                         this.bindService(intent, conn, Context.BIND_AUTO_CREATE); 
                         break; 
                 case R.id.btnUnbind: 
                         this.unbindService(conn); 
                         break; 
                } 
        } 

         // bindService() 所需的 ServiceConnection 对象 
         private ServiceConnection conn =  new ServiceConnection() { 
                @Override 
                 public  void onServiceConnected(ComponentName className, IBinder service) { 
                         
                } 
                @Override 
                 public  void onServiceDisconnected(ComponentName className) { 
                         
                } 
        }; 
         
         private String msg=""; 
         private UpdateReceiver receiver; 
         // 实现一个 BroadcastReceiver，用于接收指定的 Broadcast 
         public  class UpdateReceiver  extends BroadcastReceiver{ 

                @Override 
                 public  void onReceive(Context context, Intent intent) { 
                        msg = intent.getStringExtra( "msg"); 
                         
                        txtMsg.append(msg +  "\n"); 
                } 
                 
        } 
}

package com.webabcd.service; 

import android.app.Service; 
import android.content.Intent; 
import android.os.IBinder; 
import android.util.Log; 

// 演示 Service 的生命周期。具体信息运行程序后在 LogCat 中查看 
public  class MyService  extends Service { 

        @Override 
         public IBinder onBind(Intent intent) { 
                 
                Log.d( "MyDebug",  "onBind"); 
                sendMsg( "onBind"); 
                 
                 // TODO Auto-generated method stub 
                 return  null; 
        } 

        @Override 
         public  void onCreate() { 
                 // TODO Auto-generated method stub 
                 super.onCreate(); 
                 
                Log.d( "MyDebug",  "onCreate"); 
                sendMsg( "onCreate"); 
        } 

        @Override 
         public  void onDestroy() { 
                 // TODO Auto-generated method stub 
                 super.onDestroy(); 
                 
                Log.d( "MyDebug",  "onDestroy"); 
                sendMsg( "onDestroy"); 
        } 

        @Override 
         public  void onRebind(Intent intent) { 
                 // TODO Auto-generated method stub 
                 super.onRebind(intent); 
                 
                Log.d( "MyDebug",  "onRebind"); 
                sendMsg( "onRebind"); 
        } 

        @Override 
         public  void onStart(Intent intent,  int startId) { 
                 super.onStart(intent, startId); 
                 
                Log.d( "MyDebug",  "onStart"); 
                sendMsg( "onStart"); 
        } 
         
        @Override 
         public  boolean onUnbind(Intent intent) { 
                 
                Log.d( "MyDebug",  "onUnbind"); 
                sendMsg( "onUnbind"); 
                 
                 // TODO Auto-generated method stub 
                 return  super.onUnbind(intent); 
        } 
         
         // 发送广播信息 
         private  void sendMsg(String msg){ 
                 // 指定广播目标的 action （注：指定了此 action 的 receiver 会接收此广播） 
                Intent intent =  new Intent( "com.webabcd.service.msg"); 
                 // 需要传递的参数 
                intent.putExtra( "msg", msg); 
                 // 发送广播 
                 this.sendBroadcast(intent); 
        } 
}

package com.webabcd.service; 

import android.content.BroadcastReceiver; 
import android.content.Context; 
import android.content.Intent; 
import android.util.Log; 

public  class MyBootReceiver  extends BroadcastReceiver { 

         // 用于接收满足条件的 Broadcast（相应的 Broadcast 的注册信息详见 AndroidManifest.xml ，当系统启动完毕后会调用这个广播接收器） 
        @Override 
         public  void onReceive(Context arg0, Intent arg1) { 
                Log.d( "MyDebug",  "onReceive"); 
                 
                 // 启动服务 
                Intent service =  new Intent(arg0, MyService. class); 
                arg0.startService(service); 
        } 

}

<? xml  version ="1.0"  encoding ="utf-8" ?> 
< manifest  xmlns:android ="http://schemas.android.com/apk/res/android" 
         package ="com.webabcd.service"  android:versionCode ="1" 
         android:versionName ="1.0" > 
         < application  android:icon ="@drawable/icon"  android:label ="@string/app_name" > 
                 < activity  android:name =".Main"  android:label ="@string/app_name" > 
                         < intent-filter > 
                                 < action  android:name ="android.intent.action.MAIN"  /> 
                                 < category  android:name ="android.intent.category.LAUNCHER"  /> 
                         </ intent-filter > 
                 </ activity > 
                 
                <!--  
                        如果有需要用到的 service ，则都要在这里做相应的配置 
                --> 
                 < service  android:name =".MyService" > </ service > 
                 
                <!--  
                        注册一个 BroadcastReceiver 
                        其 intent-filter 为 android.intent.action.BOOT_COMPLETED（用于接收系统启动完毕的 Broadcast） 
                --> 
                 < receiver  android:name =".MyBootReceiver" > 
                         < intent-filter > 
                                 < action  android:name ="android.intent.action.BOOT_COMPLETED"  /> 
                         </ intent-filter > 
                 </ receiver > 
         </ application > 
         
        <!--  
                接受系统启动完毕的 Broadcast 的权限 
        --> 
         < uses-permission  android:name ="android.permission.RECEIVE_BOOT_COMPLETED"  /> 
         < uses-sdk  android:minSdkVersion ="3"  /> 
</ manifest >