Activity、Service、BroadcastReceiver的通信

目的

本应用程序包括一个活动(testActivity)和一个服务(testService), 他们各自有自己的广播接收器(MyReceiver 和TestServiceReceiver). 

当按下Start按钮, testActivity会通过意图(Intent)启动testService. 
在testService的onStartCommand()创建并启动一个线程(thread),在线程里面重复发送广播(sendBroadcast()),把当前系统时间送给testActivity的MyReceiver. 
当MyReceiver接收到,会把接收到的时间和新的系统时间比较,并把延迟时间显示出来.

当按下Stop按钮, testActivity会发送广播送给testService的TestServiceReceiver.  
当TestServiceReceiver接收到,便会停止服务.

testActivity.java

package com.testActivity;

 

import android.app.Activity;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

 

public class testActivity extends Activity {

 

 final static String MY_ACTION = "testActivity.MY_ACTION" ;

 

 TextView textData;

 

 public static final int RQS_STOP_SERVICE = 1 ;

 MyReceiver myReceiver;

 

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super .onCreate(savedInstanceState);

        setContentView(R.layout.main);

 

        textData = (TextView)findViewById(R.id.data);

        Button buttonStart = (Button)findViewById(R.id.start);

        Button buttonStop = (Button)findViewById(R.id.stop);

        buttonStart.setOnClickListener(buttonStartOnClickListener);

        buttonStop.setOnClickListener(buttonStopOnClickListener);

    }

 

    @Override

 protected void onStart() {

  // TODO Auto-generated method stub

     myReceiver = new MyReceiver();

     IntentFilter intentFilter = new IntentFilter();

     intentFilter.addAction(MY_ACTION);

     registerReceiver(myReceiver, intentFilter);   //←Squek:注册receiver等待其他Broadcast传送

  super .onStart();

 }

 

 @Override

 protected void onStop() {

  // TODO Auto-generated method stub

  unregisterReceiver(myReceiver);  //←Squek:取消注册

  super .onStop();

 }

 

 Button.OnClickListener buttonStartOnClickListener

    = new Button.OnClickListener(){

 

  @Override

  public void onClick(View arg0) {

   // TODO Auto-generated method stub

   Intent intent = new Intent(testActivity. this , com.testActivity.testService. class );

   testActivity. this .startService(intent);   //←Squek:Service启动

  }};

 

 Button.OnClickListener buttonStopOnClickListener

 = new Button.OnClickListener(){

 

  @Override

  public void onClick(View arg0) {

   // TODO Auto-generated method stub

   Intent intent = new Intent();

   intent.setAction(testService.MY_ACTION);

   intent.putExtra( "RQS" , RQS_STOP_SERVICE);

   sendBroadcast(intent);  //←Squek:Activity send Broadcast

  }};

 

  //Broadcast Receiver宣告

  private class MyReceiver extends BroadcastReceiver{

 

  @Override

  public void onReceive(Context arg0, Intent arg1) {

   // TODO Auto-generated method stub

   long timestamp = arg1.getLongExtra( "timestamp" , 0 );

   long curtime = System.currentTimeMillis();

   long delay = curtime - timestamp;

   textData.setText(String.valueOf(timestamp)

     + " : " + String.valueOf(curtime)

     + " delay " + String.valueOf(delay)

     + "(ms)" );

  }

 

 }

}

testService.java

package com.testActivity;

 

import android.app.Service;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.os.IBinder;

import android.widget.Toast;

 

public class testService extends Service {

 

 final static String MY_ACTION = "testService.MY_ACTION" ;

 

 TestServiceReceiver testServiceReceiver;

 boolean running;

 

 @Override

 public void onCreate() {

  // TODO Auto-generated method stub

  Toast.makeText(getBaseContext(),

    "TestServiceReceiver.onCreate" ,

    Toast.LENGTH_LONG).show();

  testServiceReceiver = new TestServiceReceiver();

  super .onCreate();

 }

 

 @Override

 public IBinder onBind(Intent arg0) {

  // TODO Auto-generated method stub

  return null ;

 }

 

 @Override

 public int onStartCommand(Intent intent, int flags, int startId) {

  // TODO Auto-generated method stub

  Toast.makeText(getBaseContext(),

    "TestServiceReceiver.onStartCommand" ,

    Toast.LENGTH_LONG).show();

  IntentFilter intentFilter = new IntentFilter();

  intentFilter.addAction(MY_ACTION);

  registerReceiver(testServiceReceiver, intentFilter);

  running = true ;

 

  MyThread myThread = new MyThread();

  myThread.start();

 

  return super .onStartCommand(intent, flags, startId);

 }

 

 

 

 @Override

 public void onDestroy() {

  // TODO Auto-generated method stub

  this .unregisterReceiver(testServiceReceiver);

  super .onDestroy();

 }

 

 public class MyThread extends Thread {

 

  @Override

  public void run() {

   // TODO Auto-generated method stub

 

   // TODO Auto-generated method stub

   while (running){

    try {

     Thread.sleep( 1000 );

    } catch (InterruptedException e) {

     // TODO Auto-generated catch block

     e.printStackTrace();

    }

    Intent intent = new Intent();

    intent.setAction(testActivity.MY_ACTION);

    intent.putExtra( "timestamp" , System.currentTimeMillis());

    sendBroadcast(intent);  //←Squek:Service send Broadcast

   }

  }

 

 }

 

 public class TestServiceReceiver extends BroadcastReceiver {

 

  @Override

  public void onReceive(Context arg0, Intent arg1) {

   // TODO Auto-generated method stub

   int rqs = arg1.getIntExtra( "RQS" , 0 );

   if (rqs == testActivity.RQS_STOP_SERVICE){

    Toast.makeText(getBaseContext(),

      "TestServiceReceiver.onReceive w/ RQS_STOP_SERVICE" ,

      Toast.LENGTH_LONG).show();

    running = false ;

    stopSelf();

   }

  }

 }

 

}

main.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"

    >

< TextView

    android:layout_width = "fill_parent"

    android:layout_height = "wrap_content"

    android:text = "@string/hello"

    />

< Button

 android:id = "@+id/start"

    android:layout_width = "fill_parent"

    android:layout_height = "wrap_content"

    android:text = "- Start -"

    />

< Button

 android:id = "@+id/stop"

    android:layout_width = "fill_parent"

    android:layout_height = "wrap_content"

    android:text = "- Stop -"

    />

< TextView

 android:id = "@+id/data"

    android:layout_width = "fill_parent"

    android:layout_height = "wrap_content"

    />

</ LinearLayout >

AndroidManifest.xml setting

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

< manifest xmlns:android = " http://schemas.android.com/apk/res/android"

      package = "com.testActivity"

      android:versionCode = "1"

      android:versionName = "1.0" >

    < application android:icon = "@drawable/icon" android:label = "@string/app_name" >

        < activity android:name = ".testActivity"

                  android:label = "@string/app_name" >

            < intent-filter >

                < action android:name = "android.intent.action.MAIN" />

                < category android:name = "android.intent.category.LAUNCHER" />

            </ intent-filter >

        </ activity >

  < service android:name = ".testService"

     />

    </ application >

    < uses-sdk android:minSdkVersion = "7" />

 

</ manifest >