关于广播注册方式的一点补充

前面在介绍广播时，都是在AndroidManifest里面进行注册的，这种注册方式具有常驻性，即使程序关闭，如果有广播信息来，程序也会被系统调用自动运行。还有一种方式是在代码里进行注册，这种注册方式不具有常驻性，也就是说广播跟随程序的生命周期。请看下面这个简单示例：

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();

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button sendBtn = (Button) findViewById(R.id.main_btn_send);
sendBtn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setAction(ACTION);
intent.putExtra("msg", "简单广播消息");
sendBroadcast(intent);
}
});
}

@Override
protected void onResume() {
super.onResume();
// 注册Receiver
registerReceiver(receiver, filter);
}

@Override
protected void onPause() {
super.onPause();
// 注销Receiver
unregisterReceiver(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 {

@Override
public 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();
}
}

}