当我创建扩展BrodcastReceiver并注册它的类时。
MainActivity中的错误Unable to destroy activity, Receiver not registered: null
onDestroy()函数调用unregisterReceiver时。
的onCreate():
ConnectionChangeReceiver connectionChangeReceiver = new ConnectionChangeReceiver();
IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(connectionChangeReceiver, filter);
的onDestroy():
@Override
protected void onDestroy() {
Log.v("YourActivity", "onDestroy");
unregisterReceiver(connectionChangeReceiver);
super.onDestroy();
}
ConnectionChangeReceiver类:
public class ConnectionChangeReceiver extends BroadcastReceiver
{
@Override
public void onReceive( Context context, Intent intent )
{
Toast.makeText(context, "CONN", Toast.LENGTH_SHORT).show();
}
}
清单:UPDATE:
添加<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mamrezo.mapapp" >
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.mamrezo.mapapp.MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name=".ConnectionChangeReceiver" >
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
</intent-filter>
</receiver>
</application>
</manifest>
答案 0 :(得分:1)
我始终register
onStart
中的接收者和unregister
中的onStop
。感谢这个答案,我知道这一点:https://stackoverflow.com/a/24391706/1203797
如果它仍然无法正常工作,只需将unregisterReceiver(connectionChangeReceiver);
换成try-catch
块即可,如上面发布的链接中所述。
或者您可以在manifest
中注册,例如:
<receiver android:name=".ConnectionChangeReceiver" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>