android - 倒计时进度条不工作 Android

Question

我编写了以下代码在我的 android 应用程序中创建倒计时进度条:

ProgressBar gameTimer;
CountDownTimer gameCountDownTimer;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    gameTimer = (ProgressBar)findViewById(R.id.game_timer);
    setTimer(10);
}

private void setTimer(int time) {
    progress = 100;
    final int actualTime = time*1000;
    gameTimer.setProgress(progress);
    gameCountDownTimer = new CountDownTimer(actualTime, 1000) {
        int totalTime = actualTime;
        @Override
        public void onTick(long millisUntilFinished) {
            progress = (int)(( totalTime - millisUntilFinished ) /(double)totalTime * 100);
            gameTimer.setProgress(progress);
        }

        @Override
        public void onFinish() {
            progress = 0;
            gameTimer.setProgress(progress);
            endGame();
        }
    };
}

但问题是定时器总是满的。计时器没有倒计时，也永远不会结束。上面的代码有什么问题？如何让进度条在给定时间内从填充状态到空状态倒计时？

Answer 1

你好像忘了启动 CountDownTimer，试试这个:

private void setTimer(int time) {
    progress = 100;
    final int actualTime = time*1000;
    gameTimer.setProgress(progress);
    gameCountDownTimer = new CountDownTimer(actualTime, 1000) {
        int totalTime = actualTime;
        @Override
        public void onTick(long millisUntilFinished) {
            progress = (int)(( totalTime - millisUntilFinished ) /(double)totalTime * 100);
            gameTimer.setProgress(progress);
        }

        @Override
        public void onFinish() {
            progress = 0;
            gameTimer.setProgress(progress);
            endGame();
        }
    }.start();
}

正如描述的那样here .

编辑:

您的 ProgressBar 计数是因为您误解了 millisUntilFinishrd 变量。这个变量在每次滴答时减少。因此，要使您的 ProgressBar 倒计时，您必须替换它:

progress = (int)(( totalTime - millisUntilFinished ) /(double)totalTime * 100);

通过这个:

progress = (int)( millisUntilFinished  /(double)totalTime * 100);