Detect the Android device theme (is it dark or light)

问题

You can set the theme for your app, but I'm wondering if it's possible to find out which one is used by the device. Currently, my app uses Theme.AppCompat.Light. I'd like to avoid changing the theme.

P.S. I've already tried to set it to Theme.DeviceDefault and access its ID using reflection, but no luck so far.

try {
    setTheme(android.R.style.Theme_DeviceDefault);

    Class<Context> contextClass = Context.class;
    Method getThemeMethod = contextClass.getMethod("getThemeResId");
    getThemeMethod.setAccessible(true);
    Log.d("Test", "" + getThemeMethod.invoke(this)); // Always returns 0

    PackageInfo packageInfo = getPackageManager().getPackageInfo(getPackageName(), PackageManager.GET_META_DATA);
    Log.d("Test", getResources().getResourceEntryName(packageInfo.applicationInfo.theme)); // Returns 'Theme.DeviceDefault'
} catch (Exception e) {
    Log.d("Test", "exception", e);
}

回答1:

int currentNightMode = getContext().getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;  
switch (currentNightMode) {
    case Configuration.UI_MODE_NIGHT_NO:
        // Night mode is not active, we're using the light theme
        break;
    case Configuration.UI_MODE_NIGHT_YES:
        // Night mode is active, we're using dark theme
        break;
}    

回答2:

This might help ContextThemeWrapper

来源：https://stackoverflow.com/questions/40357331/detect-the-android-device-theme-is-it-dark-or-light