保存ResourceDictionary主题

Question

我有下面的命令绑定到我的按钮，它应该检测当前使用的主题并改变它(黑暗或光明)。

  var existingResourceDictionary = Application.Current.Resources.MergedDictionaries
                .Where(rd => rd.Source != null)
                .SingleOrDefault(rd => Regex.Match(rd.Source.OriginalString, @"(\/MaterialDesignThemes.Wpf;component\/Themes\/MaterialDesignTheme\.)((Light)|(Dark))").Success);

            if (existingResourceDictionary == null)
                throw new ApplicationException("Unable to find Light/Dark base theme in Application resources.");


            if (existingResourceDictionary.Source.ToString().Contains("Light"))
            {
                Settings.Default.Theme = true;
                Settings.Default.Save();
            }
            else
            {
                Settings.Default.Theme = false;
                Settings.Default.Save();
            }

            var source =
                $"pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.{(Settings.Default.Theme ? "Dark" : "Light")}.xaml";
            var newResourceDictionary = new ResourceDictionary() { Source = new Uri(source) };

            Application.Current.Resources.MergedDictionaries.Remove(existingResourceDictionary);
            Application.Current.Resources.MergedDictionaries.Add(newResourceDictionary);

在ViewModel中(当我运行应用程序时)，它应该检测上面的按钮所做的最后更改，并应用主题。基本上，我从上面更改的设置中获得了值：

   var existingResourceDictionary = Application.Current.Resources.MergedDictionaries
          .Where(rd => rd.Source != null)
          .SingleOrDefault(rd => Regex.Match(rd.Source.OriginalString, @"(\/MaterialDesignThemes.Wpf;component\/Themes\/MaterialDesignTheme\.)((Light)|(Dark))").Success);

            if (existingResourceDictionary == null)
                throw new ApplicationException("Unable to find Light/Dark base theme in Application resources.");


            var source =
                $"pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.{(Settings.Default.Theme ? "Dark" : "Light")}.xaml";
            var newResourceDictionary = new ResourceDictionary() { Source = new Uri(source) };

            Application.Current.Resources.MergedDictionaries.Remove(existingResourceDictionary);
            Application.Current.Resources.MergedDictionaries.Add(newResourceDictionary);

代码工作正常，但我觉得我可以减少重复和缩短？

Answer 1

你可以代替

如果(existingResourceDictionary.Source.ToString().Contains("Light")) { Settings.Default.Theme = true；Settings.Default.Save()；} Settings.Default.Theme = false；Settings.Default.Save()；}

通过

Settings.Default.Theme = existingResourceDictionary.Source.ToString().Contains("Light");
Settings.Default.Save();

把它缩短一点。