呼叫广播接收器变量值丢失

Question

我正在使用电话接收器。我有此link中的所有代码。当应用程序处于前台或被杀死时，代码可以正常工作。

当应用程序在前台运行并收到用户选择的呼叫时，会出现问题。现在，在用户杀死该应用程序之间，并且在通话结束之后，变量的最后保存状态在广播接收器中声明未维护，并且无法获取任何通话时间信息和号码。任何帮助将不胜感激。

   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

        private static int lastState = TelephonyManager.CALL_STATE_IDLE;
        private static Date callStartTime;
        private static boolean isIncoming;
        private static String savedNumber;  //because the passed incoming is only valid in ringing


        @Override
        public void onReceive(Context context, Intent intent) {

            //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")) {
                savedNumber = intent.getExtras().getString("android.intent.extra.PHONE_NUMBER");
            }
            else{
                String stateStr = intent.getExtras().getString(TelephonyManager.EXTRA_STATE);
                String number = intent.getExtras().getString(TelephonyManager.EXTRA_INCOMING_NUMBER);
                int state = 0;
                if(stateStr.equals(TelephonyManager.EXTRA_STATE_IDLE)){
                    state = TelephonyManager.CALL_STATE_IDLE;
                }
                else if(stateStr.equals(TelephonyManager.EXTRA_STATE_OFFHOOK)){
                    state = TelephonyManager.CALL_STATE_OFFHOOK;
                }
                else if(stateStr.equals(TelephonyManager.EXTRA_STATE_RINGING)){
                    state = TelephonyManager.CALL_STATE_RINGING;
                }


                onCallStateChanged(context, state, number);
            }
        }

        //Derived classes should override these to respond to specific events of interest
        protected void onIncomingCallStarted(Context ctx, String number, Date start){}
        protected void onOutgoingCallStarted(Context ctx, String number, Date start){}
        protected void onIncomingCallEnded(Context ctx, String number, Date start, Date end){}
        protected void onOutgoingCallEnded(Context ctx, String number, Date start, Date end){}
        protected void onMissedCall(Context ctx, String number, Date start){}

        //Deals with actual events

        //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
        public void onCallStateChanged(Context context, int state, String number) {
            if(lastState == state){
                //No change, debounce extras
                return;
            }
            switch (state) {
                case TelephonyManager.CALL_STATE_RINGING:
                    isIncoming = true;
                    callStartTime = new Date();
                    savedNumber = number;
                    onIncomingCallStarted(context, number, callStartTime);
                    break;
                case TelephonyManager.CALL_STATE_OFFHOOK:
                    //Transition of ringing->offhook are pickups of incoming calls.  Nothing done on them
                    if(lastState != TelephonyManager.CALL_STATE_RINGING){
                        isIncoming = false;
                        callStartTime = new Date();
                        onOutgoingCallStarted(context, savedNumber, callStartTime);                     
                    }
                    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(context, savedNumber, callStartTime);
                    }
                    else if(isIncoming){
                        onIncomingCallEnded(context, savedNumber, callStartTime, new Date());                       
                    }
                    else{
                        onOutgoingCallEnded(context, savedNumber, callStartTime, new Date());                                               
                    }
                    break;
            }
            lastState = state;
        }
    }


public class CallReceiver extends PhonecallReceiver {

    @Override
    protected void onIncomingCallStarted(Context ctx, String number, Date start) {
    }

    @Override
    protected void onOutgoingCallStarted(Context ctx, String number, Date start) {
    }

    @Override
    protected void onIncomingCallEnded(Context ctx, String number, Date start, Date end) {
    }

    @Override
    protected void onOutgoingCallEnded(Context ctx, String number, Date start, Date end) {
    }

    @Override
    protected void onMissedCall(Context ctx, String number, Date start) {
    }

}