<?xml version="1.0" encoding="utf-8"?>
<resources>
  <attr name="textColor" format="color|reference" />
  <attr name="mainBackground" format="color|reference" />
</resources>

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <!-- 默認(rèn) -->
  <style name="ThemeDefault" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="mainBackground">#ffffff</item>
    <item name="textColor">#000000</item>
  </style>
  <!-- 夜間 -->
  <style name="ThemeNight" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="mainBackground">#000000</item>
    <item name="textColor">#ffffff</item>
  </style>
</resources>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android="@+id/main_screen"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  android:background="?attr/mainBackground">
  <Button
    android:id="@+id/button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:text="改變Theme"
    android:onClick="changeTheme"
    android:textColor="?attr/textColor"/>
</LinearLayout>

public void changeTheme() {
  if (isNightMode) {
    setTheme(R.style.ThemeDefault);
    isNightMode = false;
  } else {
    setTheme(R.style.ThemeNight);
    isNightMode = true;
  }
  setContentView(R.layout.activity_main);
}

private void updateTheme() {
  TypedValue typedValue = new TypedValue();
  Resources.Theme theme = getTheme();
  theme.resolveAttribute(R.attr.textColor, typedValue, true);
  findViewById(R.id.button).setBackgroundColor(typedValue.data);
  theme.resolveAttribute(R.attr.mainBackground, typedValue, true);
  findViewById(R.id.main_screen).setBackgroundColor(typedValue.data);
}

public static Drawable getDrawable(Context context, int id) {
  return context.getResources().getDrawable(getResId(id));
}

public static int getResId(int defaultResId) ｛
  if (!isNightMode()) {
    return defaultResId;
  }
  if (sResourceMap == null) {
    buildResourceMap();
  }
  int themedResId = sResourceMap.get(defaultResId);
  return themedResId == 0 ? defaultResId : themedResId;
}

private static void buildResourceMap() {
  sResourceMap = new SparseIntArray();
  sResourceMap.put(R.drawable.common_background, R.drawable.common_background_night);
  // ...
}

public static void init(Context context) {
  sRes = context.getResources();
}

public static void updateNightMode(boolean on) {
  DisplayMetrics dm = sRes.getDisplayMetrics();
  Configuration config = sRes.getConfiguration();
  config.uiMode &= ~Configuration.UI_MODE_NIGHT_MASK;
  config.uiMode |= on ? Configuration.UI_MODE_NIGHT_YES : Configuration.UI_MODE_NIGHT_NO;
  sRes.updateConfiguration(config, dm);
}

/**
* Sets the night mode. Changes to the night mode are only effective when
* the car or desk mode is enabled on a device.
*
* The mode can be one of:
* {@link #MODE_NIGHT_NO}- sets the device into notnight
* mode.
* {@link #MODE_NIGHT_YES} - sets the device into night mode.
* {@link #MODE_NIGHT_AUTO} - automatic night/notnight switching
* depending on the location and certain other sensors.
*/
public void setNightMode(int mode)

if (isDoingNightModeLocked() && mNightMode != mode) {
  Settings.Secure.putInt(getContext().getContentResolver(), Settings.Secure.UI_NIGHT_MODE, mode);
  mNightMode = mode;
  updateLocked(0, 0);
}

boolean isDoingNightModeLocked() {
  return mCarModeEnabled || mDockState != Intent.EXTRA_DOCK_STATE_UNDOCKED;
}

/**
* Bit mask of the ui mode. Currently there are two fields:
*
The {@link #UI_MODE_TYPE_MASK} bits define the overall ui mode of the
* device. They may be one of {@link #UI_MODE_TYPE_UNDEFINED},
* {@link #UI_MODE_TYPE_NORMAL}, {@link #UI_MODE_TYPE_DESK},
* {@link #UI_MODE_TYPE_CAR}, {@link #UI_MODE_TYPE_TELEVISION},
* {@link #UI_MODE_TYPE_APPLIANCE}, or {@link #UI_MODE_TYPE_WATCH}.
*
*
The {@link #UI_MODE_NIGHT_MASK} defines whether the screen
* is in a special mode. They may be one of {@link #UI_MODE_NIGHT_UNDEFINED},
* {@link #UI_MODE_NIGHT_NO} or {@link #UI_MODE_NIGHT_YES}.
*/
public int uiMode;