我有一个MainActivity类,它包含BroadcastReceiver来捕获系统广播(Internet连接和wifi扫描结果) . 我正面临一个问题,互联网连接广播正在接收并显示为Toast但是wifi扫描结果条件“if(intent.getAction() . equals(android.net.wifi.WifiManager.SCAN_RESULTS_AVAILABLE_ACTION))”未通过该程序 . 有谁知道问题出在哪里?清单中接收器的定义有问题吗?
04-08 23:16:34.319: E/AndroidRuntime(13291): FATAL EXCEPTION: main
04-08 23:16:34.319: E/AndroidRuntime(13291): Process: com.bustracker, PID: 13291
04-08 23:16:34.319: E/AndroidRuntime(13291): java.lang.RuntimeException: Unable to instantiate receiver com.bustracker.MainActivity: java.lang.ClassCastException: com.bustracker.MainActivity cannot be cast to android.content.BroadcastReceiver
04-08 23:16:34.319: E/AndroidRuntime(13291): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2518)
04-08 23:16:34.319: E/AndroidRuntime(13291): at android.app.ActivityThread.access$1800(ActivityThread.java:161)
04-08 23:16:34.319: E/AndroidRuntime(13291): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1341)
04-08 23:16:34.319: E/AndroidRuntime(13291): at android.os.Handler.dispatchMessage(Handler.java:102)
04-08 23:16:34.319: E/AndroidRuntime(13291): at android.os.Looper.loop(Looper.java:157)
04-08 23:16:34.319: E/AndroidRuntime(13291): at android.app.ActivityThread.main(ActivityThread.java:5356)
04-08 23:16:34.319: E/AndroidRuntime(13291): at java.lang.reflect.Method.invokeNative(Native Method)
04-08 23:16:34.319: E/AndroidRuntime(13291): at java.lang.reflect.Method.invoke(Method.java:515)
04-08 23:16:34.319: E/AndroidRuntime(13291): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
04-08 23:16:34.319: E/AndroidRuntime(13291): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
04-08 23:16:34.319: E/AndroidRuntime(13291): at dalvik.system.NativeStart.main(Native Method)
04-08 23:16:34.319: E/AndroidRuntime(13291): Caused by: java.lang.ClassCastException: com.bustracker.MainActivity cannot be cast to android.content.BroadcastReceiver
04-08 23:16:34.319: E/AndroidRuntime(13291): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2513)
04-08 23:16:34.319: E/AndroidRuntime(13291): ... 10 more
活动代码:
公共类MainActivity扩展ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
private BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(
android.net.ConnectivityManager.CONNECTIVITY_ACTION)) {
} else if (intent.getAction().equals(
android.net.wifi.WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {
}
}
};
protected void onResume() {
IntentFilter conn = new IntentFilter();
conn.addAction(android.net.ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(receiver, conn);
IntentFilter wifi = new IntentFilter();
wifi.addAction(android.net.wifi.WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
registerReceiver(receiver, wifi);
super.onResume();
}
@Override
protected void onPause() {
unregisterReceiver(receiver);
super.onPause();
}
}
1 回答
你有
<receiver>
元素指向MainActivity
.首先,这是错误的,因为
MainActivity
不是BroadcastReceiver
. 这就是你的异常告诉你的 .其次,您还通过
registerReceiver()
注册这些广播 . 不太可能希望 both 在清单 and 中通过registerReceiver()
进行注册 .我将首先评论
<receiver>
元素(因为它显然是错误的)并从那里开始 .