引用者:java.lang.IllegalArgumentException:未注册接收者:null [英] aused by: java.lang.IllegalArgumentException: Receiver not registered: null
问题描述
我正在尝试为Internet连接和wifi扫描结果广泛注册,但是却收到此错误。原因:java.lang.IllegalArgumentException:接收者未注册:null。互联网保密广播有效,但wifi扫描结果无效。
我很感谢您。
I am trying to register broad for internet connection and wifi scan results but I am getting this error."caused by: java.lang.IllegalArgumentException: Receiver not registered: null". The internet conccection broadcast works but not the of the wifi scan result. I Appreciate any help.
MainActivity:
MainActivity:
public class MainActivity extends ActionBarActivity {
BroadcastReceiverListener receiver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
receiver = new BroadcastReceiverListener();
}
private class BroadcastReceiverListener extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(
android.net.wifi.WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {
}
else if (intent.getAction().equals(
android.net.ConnectivityManager.CONNECTIVITY_ACTION)) {
}
}
};
protected void onResume() {
IntentFilter wifi = new IntentFilter();
wifi.addAction(android.net.wifi.WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
registerReceiver(receiver, wifi);
IntentFilter conn = new IntentFilter();
conn.addAction(android.net.ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(receiver, conn);
super.onResume();
}
@Override
protected void onDestroy() {
unregisterReceiver(receiver);
super.onDestroy();
}
}
维护:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.bustracker"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<!-- Enable to check if the wifi is available -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".BCR"
android:label="@string/title_activity_bcr" >
</activity>
</application>
</manifest>
推荐答案
您正在您的 onResume()
You are creating a new (local) BroadcastReceiver
in your onResume()
BroadcastReceiverListener receiver = new BroadcastReceiverListener();
,但是在您的 onPause()
中, code> receiver 指未初始化的实例变量,它为 null
but in your onPause()
the receiver
refers to the uninitialized instance variable which is null
unregisterReceiver(receiver); // receiver is null
因此,要解决此问题,只需实例化 receiver
在您的 onCreate()
方法中一次
So, to fix the issue just instantiate the receiver
once in your onCreate()
method
receiver = new BroadcastReceiverListener();
然后同时 onPause()
和 onResume()
将取消/注册同一实例。
Then both onPause()
and onResume()
will un/register the same instance.
这篇关于引用者:java.lang.IllegalArgumentException:未注册接收者:null的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!