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.
