在 activity 上保存倒数计时器销毁并在 onResume() 中恢复它

Question

我想启动一个 2 分钟的计数器，当 activity 销毁时，我想保存它，然后在 activity 恢复时，我想在我离开的地方启动计数器

counter = new CountDownTimer(120000, 1000) { // adjust the milli seconds here

        public void onTick(long millisUntilFinished)
        {
            textview.setText("" + String.format("%d min, %d sec",
                    TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished),
                    TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished) -
                            TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished))));

            Log.i(TAG, "onTick: "+millisUntilFinished);
        }

        public void onFinish()
        {
            textview.setText("done!");
        }
    }.start();

Answer 1

我们只是在 activity 被销毁时保存 millisUntilFinished 的值，并在 activity 再次开始时使用该值创建新的 CountDownTimer。

long millisUntilFinished;

在onDestroy()（或onStop()）

@Override
    public void onDestroy() {
        SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
        editor.putLong("millisUntilFinished", millisUntilFinished);
        editor.apply();
        super.onDestroy();
    }

并在您想要启动 CountDownTimer

时获取 millisUntilFinished 的值

        SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE);
        millisUntilFinished = prefs.getLong("millisUntilFinished", 120000);

        counter = new CountDownTimer(millisUntilFinished, 1000) { // adjust the milli seconds here

            public void onTick(long millisUntilFinished) {
                this.millisUntilFinished = millisUntilFinished;
                textview.setText("" + String.format("%d min, %d sec",
                        TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished),
                        TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished)
                                - TimeUnit.MINUTES.toSeconds(
                                TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished))));

                Log.i(TAG, "onTick: " + millisUntilFinished);
            }

            public void onFinish() {
                textview.setText("done!");
            }
        }.start();

Answer 2

将您的计数器数据存储在 onStop 方法中的共享首选项中，因为 onDestroy() 并不总是得到保证，并使用您从 onResume 方法

存储的数据启动您的计数器

在 activity 上保存倒数计时器销毁并在 onResume() 中恢复它

Save Countdowntimer on activity destroy and resume it in onResume()

android

counter

countdowntimer