需求:有时候,我们需要自己的程序在开机后自动运行;在关机时,记录一些信息到文件中.
一、开机广播监听
Android系统启动完成后会自动发出启动完成广播(android.intent.action.BOOT_COMPLETED),
所有注册了接收启动完成广播的接收器(BroadcastReceiver)都会收到此广播.
①编写一个继承BroadcastReceiver的类,接受系统启动完成广播.
package com.example.systemtest;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;/** * 系统启动完成广播接收器 * #<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" /> * @author Lone_Wolf */public class BootCompletedReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)) { //example:启动程序 Intent start = new Intent(context, MainActivity.class); start.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);// context.startActivity(start); } }}
②在AndroidManifest.xml文件里注册广播接收器.
<receiver android:name="com.example.systemtest.BootCompletedReceiver" > <intent-filter> <!-- 开机广播 --> <action android:name="android.intent.action.BOOT_COMPLETED" /> </intent-filter> </receiver>
③添加相应权限.
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
二、关机广播监听
与开机广播对应,Android系统在即将关闭时发出系统关闭广播(android.intent.action.ACTION_SHUTDOWN).
①编写一个继承BroadcastReceiver的类,接受系统关闭广播.
package com.example.systemtest;import java.io.File;import java.io.FileOutputStream;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;/** * 系统关闭广播接收器 * @author Lone_Wolf */public class ShutdownReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { if (intent.getAction().equals(Intent.ACTION_SHUTDOWN)) { //example:写入文件 FileOutputStream fos; try { fos = new FileOutputStream( android.os.Environment.getExternalStorageDirectory() + File.separator + "SysLog.txt", true); fos.write("系统退出".getBytes("utf-8")); fos.close(); } catch (Exception e) { e.printStackTrace(); } } }}
②在AndroidManifest.xml文件里注册广播接收器.
<receiver android:name="com.example.systemtest.ShutdownReceiver" > <intent-filter> <!-- 关机广播 --> <action android:name="android.intent.action.ACTION_SHUTDOWN" /> </intent-filter> </receiver>
注: onReceive中代码的执行时间不要超过5s,否则android会弹出超时dialog.
如果需要做耗时处理,可以在onReceive()里开始一个Service,让Service去做耗时处理.
最好不要用子线程,因为BroadcastReceiver的生命周期很短,子线程可能还没有结束BroadcastReceiver就先结束了.