diff --git a/Bin/SunnyUI.dll b/Bin/SunnyUI.dll
index f39c27d7..45d9edf8 100644
Binary files a/Bin/SunnyUI.dll and b/Bin/SunnyUI.dll differ
diff --git a/Bin/SunnyUI.pdb b/Bin/SunnyUI.pdb
index 21fd90f8..11e75718 100644
Binary files a/Bin/SunnyUI.pdb and b/Bin/SunnyUI.pdb differ
diff --git a/SunnyUI.Demo/Bin/SunnyUI.Demo.exe b/SunnyUI.Demo/Bin/SunnyUI.Demo.exe
index 2e4d049e..6ac054b3 100644
Binary files a/SunnyUI.Demo/Bin/SunnyUI.Demo.exe and b/SunnyUI.Demo/Bin/SunnyUI.Demo.exe differ
diff --git a/SunnyUI.Demo/Bin/SunnyUI.dll b/SunnyUI.Demo/Bin/SunnyUI.dll
index f39c27d7..45d9edf8 100644
Binary files a/SunnyUI.Demo/Bin/SunnyUI.dll and b/SunnyUI.Demo/Bin/SunnyUI.dll differ
diff --git a/SunnyUI.Demo/FMain.Designer.cs b/SunnyUI.Demo/FMain.Designer.cs
index c5f66b20..6699f4f9 100644
--- a/SunnyUI.Demo/FMain.Designer.cs
+++ b/SunnyUI.Demo/FMain.Designer.cs
@@ -99,6 +99,7 @@
             this.ClientSize = new System.Drawing.Size(1024, 720);
             this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
             this.Name = "FMain";
+            this.ShowRadius = false;
             this.Text = "SunnyUI.Net";
             this.WindowStateChange += new Sunny.UI.UIForm.OnWindowStateChange(this.FMain_WindowStateChange);
             this.Header.ResumeLayout(false);
diff --git a/SunnyUI/Forms/UIForm.cs b/SunnyUI/Forms/UIForm.cs
index 20bff713..f36899a3 100644
--- a/SunnyUI/Forms/UIForm.cs
+++ b/SunnyUI/Forms/UIForm.cs
@@ -798,7 +798,10 @@ namespace Sunny.UI
             {
                 if (InControlBox)
                 {
-                    e.Graphics.FillRoundRectangle(UIColor.Red, ControlBoxRect, 5);
+                    if (ShowRadius)
+                        e.Graphics.FillRoundRectangle(UIColor.Red, ControlBoxRect, 5);
+                    else
+                        e.Graphics.FillRectangle(UIColor.Red, ControlBoxRect);
                 }
 
                 //e.Graphics.DrawFontImage(61453, 24, Color.White, ControlBoxRect, 1);
@@ -819,7 +822,10 @@ namespace Sunny.UI
             {
                 if (InMaxBox)
                 {
-                    e.Graphics.FillRoundRectangle(btn.FillHoverColor, MaximizeBoxRect, 5);
+                    if (ShowRadius)
+                        e.Graphics.FillRoundRectangle(btn.FillHoverColor, MaximizeBoxRect, 5);
+                    else
+                        e.Graphics.FillRectangle(btn.FillHoverColor, MaximizeBoxRect);
                 }
 
                 // e.Graphics.DrawFontImage(
@@ -872,7 +878,10 @@ namespace Sunny.UI
             {
                 if (InMinBox)
                 {
-                    e.Graphics.FillRoundRectangle(btn.FillHoverColor, MinimizeBoxRect, 5);
+                    if (ShowRadius)
+                        e.Graphics.FillRoundRectangle(btn.FillHoverColor, MinimizeBoxRect, 5);
+                    else
+                        e.Graphics.FillRectangle(btn.FillHoverColor, MinimizeBoxRect);
                 }
 
                 e.Graphics.DrawLine(Color.White,
diff --git a/SunnyUI/Static/UGDI.cs b/SunnyUI/Static/UGDI.cs
index d8e5c32b..6eec087f 100644
--- a/SunnyUI/Static/UGDI.cs
+++ b/SunnyUI/Static/UGDI.cs
@@ -381,20 +381,38 @@ namespace Sunny.UI
 
         public static void DrawRoundRectangle(this Graphics g, Pen pen, Rectangle rect, int cornerRadius, bool smooth = true)
         {
-            using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+            if (cornerRadius > 0)
+            {
+                using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+                {
+                    g.Smooth(smooth);
+                    g.DrawPath(pen, path);
+                    g.Smooth(false);
+                }
+            }
+            else
             {
                 g.Smooth(smooth);
-                g.DrawPath(pen, path);
+                g.DrawRectangle(pen, rect);
                 g.Smooth(false);
             }
         }
 
         public static void FillRoundRectangle(this Graphics g, Brush brush, Rectangle rect, int cornerRadius, bool smooth = true)
         {
-            using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+            if (cornerRadius > 0)
+            {
+                using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+                {
+                    g.Smooth(smooth);
+                    g.FillPath(brush, path);
+                    g.Smooth(false);
+                }
+            }
+            else
             {
                 g.Smooth(smooth);
-                g.FillPath(brush, path);
+                g.FillRectangle(brush, rect);
                 g.Smooth(false);
             }
         }
@@ -411,17 +429,31 @@ namespace Sunny.UI
 
         public static void DrawRoundRectangle(this Graphics g, Color color, Rectangle rect, int cornerRadius, bool smooth = true)
         {
-            using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+            if (cornerRadius > 0)
             {
-                g.DrawPath(color, path, smooth);
+                using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+                {
+                    g.DrawPath(color, path, smooth);
+                }
+            }
+            else
+            {
+                g.DrawRectangle(color, rect, smooth);
             }
         }
 
         public static void FillRoundRectangle(this Graphics g, Color color, Rectangle rect, int cornerRadius, bool smooth = true)
         {
-            using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+            if (cornerRadius > 0)
             {
-                g.FillPath(color, path, smooth);
+                using (GraphicsPath path = CreateRoundedRectanglePath(rect, cornerRadius))
+                {
+                    g.FillPath(color, path, smooth);
+                }
+            }
+            else
+            {
+                g.FillRectangle(color, rect, smooth);
             }
         }
 
@@ -482,7 +514,7 @@ namespace Sunny.UI
 
         public static GraphicsPath CreateFanPath(this Point center, float d1, float d2, float startAngle, float sweepAngle)
         {
-            return new PointF(center.X,center.Y).CreateFanPath(d1,d2,startAngle,sweepAngle);
+            return new PointF(center.X, center.Y).CreateFanPath(d1, d2, startAngle, sweepAngle);
         }
 
         public static GraphicsPath CreateFanPath(this PointF center, float d1, float d2, float startAngle, float sweepAngle)
@@ -666,12 +698,12 @@ namespace Sunny.UI
             }
         }
 
-        public static void DrawString(this Graphics g, string s, Font font, Color color, 
+        public static void DrawString(this Graphics g, string s, Font font, Color color,
             RectangleF layoutRectangle, StringFormat format, float angle)
         {
-            using (Brush br= new SolidBrush(color))
+            using (Brush br = new SolidBrush(color))
             {
-                g.DrawString(s,font,br,layoutRectangle,format,angle);
+                g.DrawString(s, font, br, layoutRectangle, format, angle);
             }
         }
 
@@ -680,7 +712,7 @@ namespace Sunny.UI
         {
             using (Brush br = new SolidBrush(color))
             {
-                g.DrawString(s,font,br,point,format,angle);
+                g.DrawString(s, font, br, point, format, angle);
             }
         }