java - 每次按下按钮时都会创建一个新的计时器实例

Question

我正在设计一个递增时钟，它将在单击按钮时执行并更新 TextView 的内容，就像时间流逝一样。但是每次我按下此按钮时，前一个时钟都不会被清除，一个新实例将启动并与前一个线程并行运行。我无法理解如何阻止这种行为。以下是我的代码:

类级别变量:

 int repeatCounter = 1;
 CountDownTimer tripTimeCounter;

================================================== ===================================

  private View.OnClickListener but = new View.OnClickListener() {

    public void onClick(View v) {
        if (isOnline() == true) {
            tripTimeCounter = new CountDownTimer(60 * 1000, 1000) {

                @Override
                public void onFinish() {
                    // TODO Auto-generated method stub
                    repeatCounter = repeatCounter + 1;

                    this.start();
                    // startTimeCounter();
                }

                @Override
                public void onTick(long millisUntilFinished) {
                    // TODO Auto-generated method stub
                    timedisplay = (TextView) findViewById(R.id.textView3);
                    timedisplay.setText(formatInterval((repeatCounter * 60)
                            * 1000 - millisUntilFinished));

                }

            }.start();
            tripTimeCounter.start();
        } else {
            Toast.makeText(getApplicationContext(),
                    "Not connected to the internet", Toast.LENGTH_LONG)
                    .show();
        }
    }
};

Answer 1

只浏览了这一点，但在谷歌搜索计时器后，看到了 cancel方法，其中表示:

When a timer is no longer needed, users should call cancel(), which releases the timer's thread and other resources. Timers not explicitly cancelled may hold resources indefinitely.