Countdowntimer的TextView

Question

我创造了这个应用程序，现在我想用一个TextView来显示秒，直到其他活动开始，但我不知道怎么回事，我创建了一个txtview的countdowntimer内，但它从来没有表现出

Event=new String(Edt.getText().toString()); 
final int time = Integer.parseInt(sec.getText().toString()); 

Intent myInt = new Intent(MainActivity.this,Receiver.class); 

myInt.putExtra("key",Event); 
endingIntent pendingIntent = PendingIntent.getActivity(MainActivity.this,2,myInt,PendingIntent.FLAG_CANCEL_CURRENT); 
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE); 
am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+(time*1000),pendingIntent); 

new CountDownTimer(time*1000, 1000) { 

    @Override 
    public void onTick(long millisUntilFinished) { 
    // TODO Auto-generated method stub 
     txtV.setText("Activity starts"+millisUntilFinished/1000+"seconds"); // here is the txtV which isn't shown 
    } 

    @Override 
    public void onFinish() { 
     // TODO Auto-generated method stub 

    } 
}; 

Answer 1

首先，您需要通过拨打电话start method

启动计数器但是要小心，您只能从创建此视图的线程更改视图。你可以这样做的一种方法是：post runnable on view：

CountDownTimer timer = new CountDownTimer(time*1000, 1000) { 

     @Override 
     public void onTick(long millisUntilFinished) { 
      txtV.post(new Runnable() { 
       @Override 
       public void run() { 
          txtV.setText("Activity starts"+millisUntilFinished/1000+"seconds"); // here is the txtV which isn't shown 
       } 
      }); 
     } 

     @Override 
     public void onFinish() { 
      // TODO Auto-generated method stub 

     } 
    }; 
    timer.start();