diff --git a/SunnyUI/Controls/UITabControl.cs b/SunnyUI/Controls/UITabControl.cs
index 58a7bd76..742a6824 100644
--- a/SunnyUI/Controls/UITabControl.cs
+++ b/SunnyUI/Controls/UITabControl.cs
@@ -33,9 +33,9 @@
  * 2023-05-12: V3.3.6 重构DrawString函数
  * 2023-11-06: V3.5.2 重构主题
  * 2023-12-13: V3.6.2 优化UIPage的Init和Final加载逻辑
+ * 2024-11-29: V3.8.0 修复了SelectedIndex=-1时的报错
 ******************************************************************************/
 
-using Sunny.UI.Win32;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -43,6 +43,7 @@ using System.ComponentModel;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 using System.Windows.Forms;
+using Sunny.UI.Win32;
 
 namespace Sunny.UI
 {
diff --git a/SunnyUI/Controls/UITabControlHelper.cs b/SunnyUI/Controls/UITabControlHelper.cs
index cabddcaf..405eb2f1 100644
--- a/SunnyUI/Controls/UITabControlHelper.cs
+++ b/SunnyUI/Controls/UITabControlHelper.cs
@@ -100,7 +100,7 @@ namespace Sunny.UI
         {
             if (pageIndex < 0) return false;
 
-            if (PageItems.TryGetValue(tabControl.SelectedTab, out var fromPage))
+            if (tabControl.SelectedTab != null && PageItems.TryGetValue(tabControl.SelectedTab, out var fromPage))
             {
                 bool isCancel = fromPage.OnPageDeselecting();
                 if (isCancel) return false;
@@ -122,7 +122,7 @@ namespace Sunny.UI
         {
             if (pageGuid == Guid.Empty) return false;
 
-            if (PageItems.TryGetValue(tabControl.SelectedTab, out var fromPage))
+            if (tabControl.SelectedTab != null && PageItems.TryGetValue(tabControl.SelectedTab, out var fromPage))
             {
                 bool isCancel = fromPage.OnPageDeselecting();
                 if (isCancel) return false;
@@ -142,7 +142,7 @@ namespace Sunny.UI
 
         public UIPage GetPage(TabPage tabPage)
         {
-            if (PageItems.TryGetValue(tabControl.SelectedTab, out var uiPage))
+            if (tabControl.SelectedTab != null && PageItems.TryGetValue(tabControl.SelectedTab, out var uiPage))
                 return uiPage;
             return null;
         }