BrocastReceiver在code与在xml里头注册的区别

BrocastReceiver在code与在xml里面注册的区别
曾经在看过BroadcastReceiver在code与xml的注册的区别：在code里面注册，只有你的Activity或service处于当前运行的状态才能接受到消息，当Activity或service不处于活的状态，则是接不到消息的。而在xml里面注册的话，那样不管是否处于活的状态都可以接收到消息的。可昨天我在接受usb disconnected的消息时，我却犯错了。我在代码里面注册，而我的activity在插上usb时已经进入onpause状态了，当拔掉usb我的activity是不可能接收到usb disconnected消息的。

下面提供两种注册usb BroadcastReceiver的code:
1,在代码里面注册：

private IntentFilter umsFilter;private BroadcastReceiver mUMSReceiver = null;umsFilter = new IntentFilter(Intent.ACTION_UMS_CONNECTED);umsFilter.addAction(Intent.ACTION_UMS_DISCONNECTED);mUMSReceiver = new BroadcastReceiver() {@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stubString action = intent.getAction();System.out.println("mUMSReceiver action"+action);if (action.equals(Intent.ACTION_UMS_CONNECTED)) {//your code} else if (action.equals(Intent.ACTION_UMS_DISCONNECTED)) {//your code}}};//注册registerReceiver(mUMSReceiver, umsFilter);//取消注册unregisterReceiver(mUMSReceiver);

2，xml里面注册

//USBReceiver.java

import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;public class USBReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context arg0, Intent intent) {// TODO Auto-generated method stubString action = intent.getAction();System.out.println("mUMSReceiver action"+action); if (action.equals(Intent.ACTION_UMS_DISCONNECTED)) {}}}

//manifest.xml

<receiver android:name = ".USBReceiver"><intent-filter><action android:name="android.intent.action.UMS_DISCONNECTED" /></intent-filter></receiver>

1 楼 Coding.Ghost 2010-12-17   不错.这中小技巧还是很有实用性的.

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