diff --git a/SunnyUI/Forms/UIForm.cs b/SunnyUI/Forms/UIForm.cs
index 43edc29d..d65637b4 100644
--- a/SunnyUI/Forms/UIForm.cs
+++ b/SunnyUI/Forms/UIForm.cs
@@ -479,8 +479,8 @@ namespace Sunny.UI
 
         private void ShowMaximize(bool IsOnMoving = false)
         {
-            int screenIndex = GetMouseInScreen(MousePosition);
-            Screen screen = Screen.AllScreens[screenIndex];
+            //int screenIndex = GetMouseInScreen(MousePosition);
+            Screen screen = Screen.FromControl(this);
             if (windowState == FormWindowState.Normal)
             {
                 size = Size;
@@ -585,8 +585,8 @@ namespace Sunny.UI
 
             if (!IsDisposed && FormMoveMouseDown)
             {
-                int screenIndex = GetMouseInScreen(PointToScreen(e.Location));
-                Screen screen = Screen.AllScreens[screenIndex];
+                //int screenIndex = GetMouseInScreen(PointToScreen(e.Location));
+                Screen screen = Screen.FromControl(this);
                 if (MousePosition.Y == screen.WorkingArea.Top && MaximizeBox)
                 {
                     ShowMaximize(true);