无法阻止特定号码的拨出电话

Question

我想在我的应用程序中阻止传出呼叫我正在使用以下编码来阻止呼叫

public class MyReceiver extends BroadcastReceiver{

     Context context = null;
     private ITelephony telephonyService;
     String number;
     TelephonyManager telephony;
     String ussd = "*123456";
    @Override
  public void onReceive(Context context, Intent intent) 
  {
     if( intent.getAction().equals( Intent.ACTION_NEW_OUTGOING_CALL ) ) 
     { 
        number = intent.getExtras().getString( Intent.EXTRA_PHONE_NUMBER ); 
        Log.i( "out1", "number: " + number );           
     }
     telephony = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);
    try 
    {
         String action = intent.getAction();
         if(number.equals(ussd))
         {
              Class c = Class.forName(telephony.getClass().getName());
              Method m = c.getDeclaredMethod("getITelephony"); 
              m.setAccessible(true);
             com.android.internal.telephony.ITelephony telephonyService  = (ITelephony) m.invoke(telephony);
             telephonyService.silenceRinger();
             telephonyService.endCall();
        }
    } 
    catch (Exception e) 
    {
        e.printStackTrace();
    }

}
}

当有人拨打任何号码时，我想阻止通话，即我已经给出 * 12345 。如果我删除if(number.equals(ussd)) then i am able to block all outgoing calls but i am trying for particular number please help me to find where am i wrong ?

，此源代码正常工作