android 49 广播接收者中启动其他组件

main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/btnStartActivity"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="启动 activity" />
    <Button
        android:id="@+id/btnStartService"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="启动service" />
     <Button
        android:id="@+id/btnStopService"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="停止 service" />

</LinearLayout>

mainActivity.java

package com.sxt.day07_05;

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

public class MainActivity extends Activity implements OnClickListener{

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

    private void setListener() {
        findViewById(R.id.btnStartActivity).setOnClickListener(this);
        findViewById(R.id.btnStartService).setOnClickListener(this);
        findViewById(R.id.btnStopService).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Intent intent=new Intent();
        switch (v.getId()) {
        case R.id.btnStartActivity:
            intent.setAction("com.sxt.day07_05.start_activity");//发送一条广播，被MyReceiver接收到，
            break;
        case R.id.btnStartService:
            intent.setAction("com.sxt.day07_05.start_service");
            break;
        case R.id.btnStopService:
            intent.setAction("com.sxt.day07_05.stop_service");
            break;
        }
        sendBroadcast(intent);//发送广播
    }
}

广播接收者：

package com.sxt.day07_05;

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

public class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {//收到广播
        String action=intent.getAction();
        Intent intent2=null;
        if(action.equals("com.sxt.day07_05.start_activity")){
            //启动SecondActivity
            intent2=new Intent(context, SecondActivity.class);//context是上下文，就是发送广播的Activity
            intent2.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);//标志，一个Activity启动另一个Activity不用这个，因为2个Activity处于同一个任务栈，广播接收者没有任务栈，所以必出把SecondActivity启动在一个新的任务栈。因为每个Activity都在任务栈里面。
            context.startActivity(intent2);
        }else if(action.equals("com.sxt.day07_05.start_service")){
            intent2=new Intent(context, MyService.class);
            context.startService(intent2);//启动service
        }else if(action.equals("com.sxt.day07_05.stop_service")){
            intent2=new Intent(context, MyService.class);
            context.stopService(intent2);//停止service
        }
    }

}

广播接收者启动的service：

package com.sxt.day07_05;

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

public class MyService extends Service {
    boolean mLooper=true;//true:循环继续
    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    //service是一个后台进程，onBind，onStartCommand，onDestroy以on开头的方法都是在主线程执行的，所以为了不占用主线程的时间，这些方法里面的代码都要开辟工作线程执行。
    public int onStartCommand(Intent intent, int flags, int startId) {
        //耗时操作都要在工作线程里面写
        //即使这个service停止了，但是这个工作线程仍然不会停，
        //在Activity和service写的工作线程，即使Activity和service销毁了，这个工作线程还在执行。
        new Thread(){
            public void run() {
                while(mLooper){
                    SystemClock.sleep(1000);
                    Log.i("main","service is loop...");
                }
            };
        }.start();
        return super.onStartCommand(intent, flags, startId);
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        mLooper=false;//service销毁工作线程不会停止，因此要mLooper=false
    }
}

广播接收者启动的Activity：

package com.sxt.day07_05;

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

public class SecondActivity extends Activity {

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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.second, menu);
        return true;
    }

}

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".SecondActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="SecondActivity" />

</RelativeLayout>

系统描述文件：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sxt.day07_05"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.sxt.day07_05.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>

        <receiver android:name="com.sxt.day07_05.MyReceiver" >   一个广播接收者接收3个action,3个字符串，3个频道的广播，
            <intent-filter>
                <action android:name="com.sxt.day07_05.start_activity" />
                <action android:name="com.sxt.day07_05.start_service" />
                <action android:name="com.sxt.day07_05.stop_service" />
            </intent-filter>
        </receiver>

        <service android:name="com.sxt.day07_05.MyService" />    声明service

        <activity                                                                        声明activity
            android:name="com.sxt.day07_05.SecondActivity"
            android:label="@string/title_activity_second" >
        </activity>
    </application>

</manifest>