当 Android 中的应用配置更改时，计时器会重置

Question

我使用 Chronometer 和 ViewModel 创建了一个秒表应用程序，该应用程序在配置更改之前运行良好。当屏幕旋转时，秒表重置为 00:00.

this is part of StopwatchTabFrag.java.

stopwatchTabViewModel.buttonIcon.observe(getViewLifecycleOwner(), new Observer<Integer>() {
            @Override
            public void onChanged(Integer imgId) {

                switch (imgId){
                    //when the icon is changed to pause (or) when user clicks play icon then Stopwatch is start.
                    case R.drawable.ic_round_pause_circle_filled_24:
                        binding.stop.setVisibility(View.VISIBLE);
                        binding.startPause.setImageResource(imgId);
                        stopwatchTabViewModel.startStopwatch(stopwatchChronometer);
                        break;
                    //when the icon is changed to start (or) when user clicks pause icon then Stopwatch is pause.
                    case R.drawable.ic_round_play_arrow_24:
                        binding.startPause.setImageResource(imgId);
                        stopwatchTabViewModel.pauseStopwatch(stopwatchChronometer);
                        break;
                    case R.drawable.ic_round_stop_24:
                        binding.stop.setVisibility(View.GONE);
                        stopwatchTabViewModel.stopStopwatch(stopwatchChronometer);
                }
            }
        });

每当更改特定按钮图标时，我都会使用 Observer 来执行此特定任务。

this is part of StopwatchTabViewModel.java.

public void startStopwatch(Chronometer chronometer){
        if (!isRunning.getValue()){
            chronometer.setBase(SystemClock.elapsedRealtime()-pauseOfset.getValue());
            chronometer.start();
            _isRunning.setValue(true);
        }
    }

    public void pauseStopwatch(Chronometer chronometer){
        if (isRunning.getValue()){
            chronometer.stop();
            _pauseOfset.setValue(SystemClock.elapsedRealtime()-chronometer.getBase());
            _isRunning.setValue(false);
        }
    }

    public void stopStopwatch(Chronometer chronometer){
        chronometer.setBase(SystemClock.elapsedRealtime());
        _pauseOfset.setValue(0L);
        chronometer.stop();

        //Reset the icon to Start
        _buttonIcon.setValue(R.drawable.ic_round_play_arrow_24);
    }

我在 ViewModel class 中实现了秒表任务方法。不知道对不对

期待你的回答

Answer 1

将此行添加到清单中的 Activity 声明中：

android:configChanges="orientation|screenSize|screenLayout|keyboardHidden"

它将防止 Activity 在旋转时破坏（因此也是你的计时），你必须自己处理 onConfigurationChanged 方法调用中的旋转（你可能不需要在你的例）

HERE 你有一些关于配置更改的信息。

当 Android 中的应用配置更改时，计时器会重置

Chronometer is reset on when the app configuration changes in Android

java

android

chronometer

android-viewmodel