private void OnSwitchTheme(SwitchThemeMessage message)
        {
            if (message.HandlingResult == null)
            {
                message.HandlingResult = false;
            }
            var resourceString = message.ThemeName;
            if (SwitchThemeMessage.CustomThemeKey.Equals(message.ThemeName, StringComparison.Ordinal))
            {
                if (SupportCustom)
                {
                    resourceString = ShowUpOpenResourceDialog("ThemeFileFilter");
                    if (resourceString == null)
                    {
                        message.HandlingResult = true;
                        return;
                    }
                    else
                    {
                        Settings.Default.CustomThemeFile = resourceString;
                    }
                }
                else
                {
                    resourceString = ResourceFormat.InvariantFormat(Settings.Default.CurrentTheme);
                }
            }
            else
            {
                resourceString = ResourceFormat.InvariantFormat(message.ThemeName);
            }

            if (SwitchResource(resourceString))
            {
                message.HandlingResult = true;
            }
            else
            {
                Settings.Default.CurrentTheme = message.ThemeName;
            }
        }
 private void OnSwitchTheme(SwitchThemeMessage message)
 {
     TriggerPropertyChanged("IsChecked");
 }