背景知识:当Android启动时,会发出一个系统广播,内容为ACTION_BOOT_COMPLETED,它的字符串常量表示为android.intent.action.BOOT_COMPLETED。只要在程序中“捕捉”到这个消息,再启动之即可。记住,Android框架说:Don't call me, I'll call you back。我们要做的是做好接收这个消息的准备,而实现的手段就是实现一个BroadcastReceiver。
代码解析:
1、界面Activity:SayHello.java
package com.ghstudio.BootStartDemo; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class SayHello extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); TextView tv = new TextView(this); tv.setText("Hello. I started!"); setContentView(tv); } }
这段代码很简单,当Activity启动时,创建一个TextView,用它显示"Hello. I started!"字样。
2、接收广播消息:BootBroadcastReceiver.java
package com.ghstudio.BootStartDemo; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; public class BootBroadcastReceiver extends BroadcastReceiver { static final String ACTION = "android.intent.action.BOOT_COMPLETED"; @Override public void onReceive(Context context, Intent intent) { if (intent.getAction().equals(ACTION)){ Intent sayHelloIntent=new Intent(context,SayHello.class); sayHelloIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); context.startActivity(sayHelloIntent); } } }
该类派生自BroadcastReceiver,覆载方法onReceive中,检测接收到的Intent是否符合BOOT_COMPLETED,如果符合,则启动SayHello那个Activity。
3、配置文件:AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.ghstudio.BootStartDemo" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".SayHello" 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=".BootBroadcastReceiver"> <intent-filter> <action android:name="android.intent.action.BOOT_COMPLETED" /> </intent-filter> </receiver> </application> <uses-sdk android:minSdkVersion="3" /> <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"></uses-permission> </manifest>
注意其中粗体字那一部分,该节点向系统注册了一个receiver,子节点intent-filter表示接收 android.intent.action.BOOT_COMPLETED消息。不要忘记配置 android.permission.RECEIVE_BOOT_COMPLETED权限。
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1.要做的就是监听系统发出的broadcast
public class FlorenceText extends BroadcastReceiver{ public void onReceive(Context context, Intent intent) { if(Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())){ start(context); } } }
2.在AndroidMenifest.xml里还要将receiver加上, 并写明程序的入口就是FlorenceTest
<application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <receiver android:name=".main.FlorenceTest" android:exported="true" android:process=":remote"> <intent-filter > <action android:name="android.intent.action.BOOT_COMPLETED" /> <category android:name="android.intent.category.HOME"/> </intent-filter> </receiver> </application>
这样,程序就可以在开机时自动运行了
转自:http://blog.csdn.net/wh_19910525/article/details/7921685