update in themes.

Author: yanjinhuagood

SoftwareHelper/Helpers/ThemesHelper.cs

@@ -21,7 +21,9 @@ public static void SetLightDark(bool isDark)
             {
                 var existingResourceDictionary = Application.Current.Resources.MergedDictionaries
                                                     .Where(rd => rd.Source != null)
-                                                    .SingleOrDefault(rd => rd.Source.OriginalString.Contains("Light") || rd.Source.OriginalString.Contains("Dark"));
+                                                    .SingleOrDefault(rd => rd.Source.OriginalString.Contains("/SoftwareHelper;component/Themes") 
+                                                    && 
+                                                    (rd.Source.OriginalString.Contains("Light") || rd.Source.OriginalString.Contains("Dark")));
                 var source = $"pack://application:,,,/SoftwareHelper;component/Themes/{(isDark ? "Dark" : "Light")}.xaml";
                 var newResourceDictionary = new ResourceDictionary() { Source = new Uri(source) };
                 App.Current.Resources.MergedDictionaries.Remove(existingResourceDictionary);