Question

I wanted to implement an app that prevents calls like a firewall. When I debug my app, I found that when there is a call in, the onCallStateChanged() function in interface PhoneStateListener is invoked three times. As a result, preventing one call can result in three logs. I’m so confused!!

my code:

    @Override
    public void onCallStateChanged(int state, String incomingNumber) {
        try {
            if (state == TelephonyManager.CALL_STATE_RINGING && 
                PhoneUtil.getITelephony(tpm).isRinging()) {
                String flag = isBlockCall(myContext, myHelper, myTypes, incomingNumber);
                if (flag.length() > 0) {
                    blockCall();
                    myHelper.insertLog(new String[] { flag, incomingNumber, String.valueOf(System.currentTimeMillis()), null });
                    showNotification(myContext, incomingNumber, System.currentTimeMillis());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        super.onCallStateChanged(state, incomingNumber);
    }
}, PhoneStateListener.LISTEN_CALL_STATE);

Answer 1

PinkyJie,

onCallStateChanged() is working with BroadcastReceiver. so onCallStateChanged() will always get called whenever call state get changed. There are three call states.

TelephonyManager.CALL_STATE_IDLE: Phone is in idle mode, no call action.
TelephonyManager.CALL_STATE_OFFHOOK: At least one call is active in any kind.
TelephonyManager.CALL_STATE_RINGING: A new call arrived and is ringing or waiting.
TelephonyManager.

system will never go beyond that. please refer this link http://developer.android.com/reference/android/telephony/TelephonyManager.html

public class TestPhoneStateListener extends PhoneStateListener{

  public void onCallStateChanged(int state, String incomingNumber) {
    // TODO Auto-generated method stub
    System.out.println("aaaaaaaaaaaaaaa----------------------------------"+state);
    try {
        if (state == TelephonyManager.CALL_STATE_RINGING ) {
        }
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    super.onCallStateChanged(state, incomingNumber);
  }
}