java、Android 中的 运行 app 是否可以在不重置的情况下使用 switchCompat?

Is there anyway to use switchCompat without resetting while running app in java, Android?

我正在安装秒表应用程序。 我在主布局上有不同背景的 Switchcompat。 当我在 运行 的时候点击开关时,它被重置为 00:00:00.

有没有什么方法可以在不重置定时器的情况下使用开关?

下面是部分代码。

MainActivity

    SwitchCompat switchCompat;
    SharedPreferences sharedPreferences = null;

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

        switchCompat = findViewById(R.id.switchCompat);
        sharedPreferences = getSharedPreferences("night", 0);
        Boolean booleanValue = sharedPreferences.getBoolean("NightMode", false);
        if (booleanValue) {
            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
            switchCompat.setChecked(true);
        }

        switchCompat.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
                    switchCompat.setChecked(true);
                    SharedPreferences.Editor editor = sharedPreferences.edit();
                    editor.putBoolean("NightMode", true);
                    editor.commit();
                }else {
                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
                    switchCompat.setChecked(false);
                    SharedPreferences.Editor editor = sharedPreferences.edit();
                    editor.putBoolean("NightMode", false);
                    editor.commit();
                }
            }
        });
    }

签出 saving instance state pattern - 存储时间值并在 Activity 重新创建时重新存储

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    super.onSaveInstanceState(savedInstanceState);
    savedInstanceState.putString("SwitchText", switchCompat.getText().toString());
}

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

    switchCompat = findViewById(R.id.switchCompat);
    if (savedInstanceState != null) { // is null on first start
        String switchText = savedInstanceState.getString("SwitchText");
        // may be null when no value stored under given key
        if (switchText != null) switchCompat.setText(switchText);
    }
    ...

Activity 得到 recreated/restared 因为在 onCheckedChanged 中你正在调用 AppCompatDelegate.setDefaultNightMode - 这迫使 Activity 重新启动并应用新主题,你有编写一些额外的代码来保存以前的状态