關於廣播註冊方式的一點補充

前面在介紹廣播時，都是在AndroidManifest裡面進行註冊的，這種註冊方式具有常駐性，即使程式關閉，如果有廣播資訊來，程式也會被系統調用自動運行。還有一種方式是在代碼裡進行註冊，這種註冊方式不具有常駐性，也就是說廣播跟隨程式的生命週期。請看下面這個簡單樣本：

Activity：

package com.home.activity;import android.app.Activity;import android.content.Intent;import android.content.IntentFilter;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import com.home.R;import com.home.receiver.MyBroadCastReceiver;public class MainActivity extends Activity {public static final String ACTION = "com.home.receiver";private IntentFilter filter = new IntentFilter(ACTION);private MyBroadCastReceiver receiver = new MyBroadCastReceiver();@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);Button sendBtn = (Button) findViewById(R.id.main_btn_send);sendBtn.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent();intent.setAction(ACTION);intent.putExtra("msg", "簡單廣播訊息");sendBroadcast(intent);}});}@Overrideprotected void onResume() {super.onResume();// 註冊ReceiverregisterReceiver(receiver, filter);}@Overrideprotected void onPause() {super.onPause();// 登出ReceiverunregisterReceiver(receiver);}}

MyBroadCastReceiver：

package com.home.receiver;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast;public class MyBroadCastReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {if ("com.home.receiver".equals(intent.getAction())) {String msg = intent.getStringExtra("msg");Toast.makeText(context, "收到" + msg, Toast.LENGTH_LONG).show();}}}