fixed a bug of BlurWindow

HandyControlDemo/Data/AppConfig.cs

@@ -7,7 +7,7 @@ namespace HandyControlDemo.Data
     {
         public static string SavePath = $"{AppDomain.CurrentDomain.BaseDirectory}AppConfig.json";
 
-        public string Lang { get; set; } = "cn";
+        public string Lang { get; set; } = "zh-cn";
 
         public SkinType Skin { get; set; }
     }