如何让TelephonyManager听原始呼叫状态？

Question

我正在做一个电话拨号器，我在Android Manifest中使用Receiver和intent-filter。在Receiver中，我让TelephonyManager听取我的通话状态。我的问题是：我如何以及在哪里（在Receiver或其他地方）使TelephonyManager能够收听原始呼叫状态？

Android Manifest中的接收器

<receiver android:name="com.SetAndGet.amadey.myapplication5.MyReceiver2" >
            <intent-filter>
                <action android:name="android.intent.action.NEW_OUTGOING_CALL" />
            </intent-filter>
        </receiver>

代码：

@Override
    public void onReceive(final Context context, Intent intent) {
        Log.i("Point_1","onReceive");
        TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
        telephonyManager.listen(new PhoneStateListener(){
            @Override
            public void onCallStateChanged(int state, String incomingNumber) {
                if(state==0){context.startActivity(new Intent(context,MyActivity.class));
                }else if(state==2){context.stopService(new Intent(context,MyService.class));
                }else if(state==1){context.stopService(new Intent(context,MyService.class));}
            }
        },PhoneStateListener.LISTEN_CALL_STATE);
    }