Note when custom dialog themes

Note when custom themes for dialogs

1. Beware of the theme and style when apply theme attribute. this is correct <item name="android:alertDialogTheme">@style/DialogTheme</item>
2. Distinct and support at least two themes for pre-L and post-L devices
3. If you want to apply to your AlertDialog a theme different than the one specified in your Activity’s theme, you can use a ContextThemeWrapper around your current context:

ContextThemeWrapper ctw = new ContextThemeWrapper(this, R.style.DialogTheme);
        final AlertDialog.Builder builder = new AlertDialog.Builder(ctw);