如何取消注册BroadcastReceiver

Question

我的应用程序使用BroadcastReceiver以这种方式获取短信:

SmsBR.java

public class SmsBR extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        Bundle bundle = intent.getExtras();
        if (bundle != null) {
            Object[] pdus = (Object[])bundle.get("pdus");
            final SmsMessage[] messages = new SmsMessage[pdus.length];

            for (int i = 0; i < pdus.length; i++) {
                messages[i] = SmsMessage.createFromPdu((byte[])pdus[i]);
            }
            if (messages.length > 0)
                //doSomething();
            }
        }
    }
}

的Manifest.xml

<application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".Activity" 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=".SmsBR">
        <intent-filter>
            <action android:name="android.provider.Telephony.SMS_RECEIVED"></action>
        </intent-filter>
    </receiver>
</application>    

这样SmsBR始终开启.我希望在服务启动时注册它(onCreate())并在服务被销毁时取消注册(onDestroy()).我怎样才能做到这一点？

Answer 1

编辑:

对于活动:

要从您的应用程序中注册您的广播接收器,首先,<receiver>从AndroidManifest.xml文件中删除该标签.然后,打电话给registerReceiver(BroadcastReceiver receiver, IntentFilter filter)你onResume().使用unregisterReceiver(BroadcastReceiver receiver)您的onPause()注销广播接收机.

对于服务:

从清单文件中删除接收器标记.然后,您可以使用相同的方法注册您的广播接收器,onCreate()并取消注册onDestroy().

编辑:示例代码:

public class MyActivity extends Activity {
  private final BroadcastReceiver mybroadcast = new SmsBR();

  public void onResume() {
    super.onResume();

    IntentFilter filter = new IntentFilter();
    filter.addAction("android.provider.Telephony.SMS_RECEIVED");
    registerReceiver(mybroadcast, filter);
  }

  public void onPause() {
    super.onPause();

    unregisterReceiver(mybroadcast);
  }
}

Answer 2

onDestroy()不保证被称为.当您从Activty开始活动,onPause()并onStop()调用,而不是方法onDestroy().

onDestroy()按回按钮或呼叫finish()方法时调用.

因此,广播接收机应在注册onStart()或onResume(),在注销接收器onPause()或onStop().

如果在onDestroy()方法中取消注册接收器,则可能会导致App中的内存泄漏.