diff --git a/Bin/net40/SunnyUI.dll b/Bin/net40/SunnyUI.dll
index 179b30c1..11b95c75 100644
Binary files a/Bin/net40/SunnyUI.dll and b/Bin/net40/SunnyUI.dll differ
diff --git a/SunnyUI.Demo.sln b/SunnyUI.Demo.sln
new file mode 100644
index 00000000..df4086ba
--- /dev/null
+++ b/SunnyUI.Demo.sln
@@ -0,0 +1,23 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2010
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SunnyUI.Demo", "SunnyUI.Demo\SunnyUI.Demo.csproj", "{6AE19B87-C2AA-4C56-BC26-1C343F30FF58}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{6AE19B87-C2AA-4C56-BC26-1C343F30FF58}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6AE19B87-C2AA-4C56-BC26-1C343F30FF58}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6AE19B87-C2AA-4C56-BC26-1C343F30FF58}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6AE19B87-C2AA-4C56-BC26-1C343F30FF58}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {6A916817-9F8C-4A1B-87CA-7DFD5453C40A}
+	EndGlobalSection
+EndGlobal
diff --git a/SunnyUI.Demo/Bin/SunnyUI.Demo.exe b/SunnyUI.Demo/Bin/SunnyUI.Demo.exe
index b9fa45d1..79311e88 100644
Binary files a/SunnyUI.Demo/Bin/SunnyUI.Demo.exe and b/SunnyUI.Demo/Bin/SunnyUI.Demo.exe differ
diff --git a/SunnyUI.Demo/Controls/FCombobox.cs b/SunnyUI.Demo/Controls/FCombobox.cs
index f18acca9..8646dbb1 100644
--- a/SunnyUI.Demo/Controls/FCombobox.cs
+++ b/SunnyUI.Demo/Controls/FCombobox.cs
@@ -108,8 +108,9 @@ namespace Sunny.UI.Demo
 
         private void uiComboDataGridView1_ValueChanged(object sender, object value)
         {
-            if (value is DataGridViewRow row)
+            if (value is DataGridViewRow)
             {
+                DataGridViewRow row = (DataGridViewRow)value;
                 uiComboDataGridView1.Text = row.Cells["Column1"].Value.ToString();
             }
             else
diff --git a/SunnyUI.Demo/Controls/FContextMenuStrip.cs b/SunnyUI.Demo/Controls/FContextMenuStrip.cs
index 77c5434f..37745e63 100644
--- a/SunnyUI.Demo/Controls/FContextMenuStrip.cs
+++ b/SunnyUI.Demo/Controls/FContextMenuStrip.cs
@@ -21,8 +21,9 @@ namespace Sunny.UI.Demo
         private void Item_Click(object sender, EventArgs e)
         {
             ToolStripMenuItem item = (ToolStripMenuItem)sender;
-            if (item.Tag != null && item.Tag is UIStyle style)
+            if (item.Tag != null && item.Tag is UIStyle)
             {
+                UIStyle style = (UIStyle)item.Tag;
                 this.Style = style;
             }
         }
diff --git a/SunnyUI.Demo/FMain.cs b/SunnyUI.Demo/FMain.cs
index 2208b63a..d2e64189 100644
--- a/SunnyUI.Demo/FMain.cs
+++ b/SunnyUI.Demo/FMain.cs
@@ -91,11 +91,13 @@ namespace Sunny.UI.Demo
 
             //根据页面类型获取页面
             FButton page = GetPage<FButton>();
-            page?.Text.WriteConsole();
+            if (page != null)
+                page.Text.WriteConsole();
 
             //根据页面索引获取页面
             UIPage page1 = GetPage(1002);
-            page1?.Text.WriteConsole();
+            if (page1 != null)
+                page1.Text.WriteConsole();
         }
 
         /// <summary>
@@ -131,7 +133,8 @@ namespace Sunny.UI.Demo
 
         private void FMain_Selecting(object sender, TabControlCancelEventArgs e, UIPage page)
         {
-            Console.WriteLine(page?.Text);
+            if (page != null)
+                Console.WriteLine(page.Text);
         }
 
         private void 关于ToolStripMenuItem1_Click(object sender, EventArgs e)
diff --git a/SunnyUI.Demo/Units/UMapperDemo.cs b/SunnyUI.Demo/Units/UMapperDemo.cs
index 1734d5a5..17bfd720 100644
--- a/SunnyUI.Demo/Units/UMapperDemo.cs
+++ b/SunnyUI.Demo/Units/UMapperDemo.cs
@@ -14,7 +14,6 @@ namespace Sunny.UI.Demo
             t1.C = 768;
             t1.D = DateTime.Now;
             t1.E = new Point(100, 200);
-            t1.F = new MapperT3("Struct String", '\n', new MapperT4("I am T4"));
             t1.G = new Size(100, 200);
             t1.H = new List<string>() { "AA", "BB" };
             t1.I = new string[2] { "AA", "BB" };
@@ -38,8 +37,6 @@ namespace Sunny.UI.Demo
 
         public Point E { get; set; }
 
-        public MapperT3 F { get; set; }
-
         public Size G { get; set; }
 
         public List<string> H { get; set; }
@@ -59,8 +56,6 @@ namespace Sunny.UI.Demo
 
         public Point E { get; set; }
 
-        public MapperT3 F { get; set; }
-
         [MapperIgnore]
         public Size G { get; set; }
 
@@ -69,21 +64,6 @@ namespace Sunny.UI.Demo
         public string[] I { get; set; }
     }
 
-    public struct MapperT3
-    {
-        public string String { get; set; }
-        public char Char { get; set; }
-
-        public MapperT4 T4 { get; set; }
-
-        public MapperT3(string str, char c, MapperT4 t4)
-        {
-            String = str;
-            Char = c;
-            T4 = t4;
-        }
-    }
-
     public class MapperT4
     {
         public string String { get; set; }