Android 广播

广播的动态注册

public class MainActivity extends Activity {
private IntentFilter intentFilter;
private NetworkChangeReceiver networkChangeReceiver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
intentFilter = new IntentFilter();
intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
networkChangeReceiver = new NetworkChangeReceiver();
registerReceiver(networkChangeReceiver, intentFilter);
}
@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(networkChangeReceiver);
}
class NetworkChangeReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "network changes",
Toast.LENGTH_SHORT).show();
}
}
}

动态注册的广播接收器一定都要取消注册才行，这里我们是在onDestroy()
方法中通过调用unregisterReceiver()方法来实现的。

静态注册

public class BootCompleteReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "Boot Complete", Toast.LENGTH_LONG).show();
}
}

在AndroidManifest.xml 文件添加

<receiver android:name=".BootCompleteReceiver" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>

发送广播：

button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent("com.example.broadcasttest.
MY_BROADCAST");
sendBroadcast(intent);
}
});

sendOrderedBroadcast()是发送有序广播，sendOrderedBroadcast()方法接收两个参数，第一个参数仍然是
Intent，第二个参数是一个与权限相关的字符串。