这是扩展BroadcastReceiver的接收器代码。每次我安装它并且电话铃响它突然停止并发出此错误。我在这里找到了这段代码How to detect incoming calls, in an Android device?
public abstract class PhonecallReceiver extends BroadcastReceiver {
//The receiver will be recreated whenever android feels like it. We need a static variable to remember data between instantiations
static PhonecallStartEndDetector listener;
String outgoingSavedNumber;
protected Context savedContext;
@Override
public void onReceive(Context context, Intent intent) {
savedContext = context;
if(listener == null){
listener = new PhonecallStartEndDetector();
}
//We listen to two intents. The new outgoing call only tells us of an outgoing call. We use it to get the number.
if (intent.getAction().equals("android.intent.action.NEW_OUTGOING_CALL")) {
listener.setOutgoingNumber(intent.getExtras().getString("android.intent.extra.PHONE_NUMBER"));
return;
}
//The other intent tells us the phone state changed. Here we set a listener to deal with it
TelephonyManager telephony = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);
telephony.listen(listener, PhoneStateListener.LISTEN_CALL_STATE);
}
//Derived classes should override these to respond to specific events of interest
protected abstract void onIncomingCallStarted(String number, Date start);
protected abstract void onOutgoingCallStarted(String number, Date start);
protected abstract void onIncomingCallEnded(String number, Date start, Date end);
protected abstract void onOutgoingCallEnded(String number, Date start, Date end);
protected abstract void onMissedCall(String number, Date start);
//Deals with actual events
public class PhonecallStartEndDetector extends PhoneStateListener {
int lastState = TelephonyManager.CALL_STATE_IDLE;
Date callStartTime;
boolean isIncoming;
String savedNumber; //because the passed incoming is only valid in ringing
public PhonecallStartEndDetector() {}
//The outgoing number is only sent via a separate intent, so we need to store it out of band
public void setOutgoingNumber(String number){
savedNumber = number;
}
//Incoming call- goes from IDLE to RINGING when it rings, to OFFHOOK when it's answered, to IDLE when its hung up
//Outgoing call- goes from IDLE to OFFHOOK when it dials out, to IDLE when hung up
@Override
public void onCallStateChanged(int state, String incomingNumber) {
super.onCallStateChanged(state, incomingNumber);
if(lastState == state){
return;
}
switch (state) {
case TelephonyManager.CALL_STATE_RINGING:
isIncoming = true;
callStartTime = new Date();
savedNumber = incomingNumber;
onIncomingCallStarted(incomingNumber, callStartTime);
Log.i("", "2");
break;
case TelephonyManager.CALL_STATE_OFFHOOK:
//Transition of ringing->offhook are pickups of incoming calls. Nothing donw on them
if(lastState != TelephonyManager.CALL_STATE_RINGING){
isIncoming = false;
callStartTime = new Date();
onOutgoingCallStarted(savedNumber, callStartTime);
Log.i("", "3");
}
break;
case TelephonyManager.CALL_STATE_IDLE:
//Went to idle- this is the end of a call. What type depends on previous state(s)
if(lastState == TelephonyManager.CALL_STATE_RINGING){
//Ring but no pickup- a miss
onMissedCall(savedNumber, callStartTime);
Log.i("", "4");
}
else if(isIncoming){
onIncomingCallEnded(savedNumber, callStartTime, new Date());
Log.i("", "5");
}
else{
onOutgoingCallEnded(savedNumber, callStartTime, new Date());
Log.i("", "6");
}
break;
}
lastState = state;
}
}
}
错误：
10-09 09:51:08.656: E/AndroidRuntime(4249): FATAL EXCEPTION: main
10-09 09:51:08.656: E/AndroidRuntime(4249): java.lang.RuntimeException: Unable to instantiate receiver android.call.PhonecallReceiver: java.lang.InstantiationException: can't instantiate class android.call.PhonecallReceiver
10-09 09:51:08.656: E/AndroidRuntime(4249): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2460)
10-09 09:51:08.656: E/AndroidRuntime(4249): at android.app.ActivityThread.access$1500(ActivityThread.java:150)
10-09 09:51:08.656: E/AndroidRuntime(4249): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1374)
10-09 09:51:08.656: E/AndroidRuntime(4249): at android.os.Handler.dispatchMessage(Handler.java:99)
10-09 09:51:08.656: E/AndroidRuntime(4249): at android.os.Looper.loop(Looper.java:213)
10-09 09:51:08.656: E/AndroidRuntime(4249): at android.app.ActivityThread.main(ActivityThread.java:5225)
10-09 09:51:08.656: E/AndroidRuntime(4249): at java.lang.reflect.Method.invokeNative(Native Method)
10-09 09:51:08.656: E/AndroidRuntime(4249): at java.lang.reflect.Method.invoke(Method.java:525)
10-09 09:51:08.656: E/AndroidRuntime(4249): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
10-09 09:51:08.656: E/AndroidRuntime(4249): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
10-09 09:51:08.656: E/AndroidRuntime(4249): at dalvik.system.NativeStart.main(Native Method)
10-09 09:51:08.656: E/AndroidRuntime(4249): Caused by: java.lang.InstantiationException: can't instantiate class android.call.PhonecallReceiver
10-09 09:51:08.656: E/AndroidRuntime(4249): at java.lang.Class.newInstanceImpl(Native Method)
10-09 09:51:08.656: E/AndroidRuntime(4249): at java.lang.Class.newInstance(Class.java:1130)
10-09 09:51:08.656: E/AndroidRuntime(4249): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2455)
10-09 09:51:08.656: E/AndroidRuntime(4249): ... 10 more
答案 0 :(得分：1)
您无法实例化抽象类。您必须使其成为普通公共类，并在清单文件中定义它。 希望能起作用