* UIForm: 修复PageSelected可能未显示选中页面的问题

SunnyUI/Forms/UIForm.cs

@@ -44,6 +44,7 @@
  * 2022-09-11: V3.2.3 修复继承页面可响应WM_HOTKEY消息
  * 2022-11-30: V3.3.0 增加RemoveAllPages函数
  * 2023-01-25: V3.3.1 最大化后，关闭按钮扩大至原按钮右上角全部区域
+ * 2023-02-24: V3.3.2 修复PageSelected可能未显示选中页面的问题
 ******************************************************************************/
 
 using System;
@@ -2161,9 +2162,30 @@ namespace Sunny.UI
 
                 mainTabControl.PageAdded += DealPageAdded;
                 mainTabControl.PageRemoved += DealPageRemoved;
+                mainTabControl.Selecting += MainTabControl_Selecting;
             }
         }
 
+        private void MainTabControl_Selecting(object sender, TabControlCancelEventArgs e)
+        {
+            List<UIPage> pages = e.TabPage.GetControls<UIPage>();
+            if (pages.Count == 1)
+            {
+                SelectedPage = pages[0];
+                PageSelected?.Invoke(this, new UIPageEventArgs(SelectedPage));
+            }
+            else
+            {
+                SelectedPage = null;
+                PageSelected?.Invoke(this, new UIPageEventArgs(SelectedPage));
+            }
+        }
+
+        [Browsable(false)]
+        public UIPage SelectedPage { get; private set; }
+
+        public event OnUIPageChanged PageSelected;
+
         public UIPage AddPage(UIPage page, int pageIndex)
         {
             page.PageIndex = pageIndex;
@@ -2187,7 +2209,6 @@ namespace Sunny.UI
 
             page.Frame = this;
             page.OnFrameDealPageParams += Page_OnFrameDealPageParams;
-            page.PageSelected += DealPageSelected;
             MainTabControl?.AddPage(page);
             return page;
         }
@@ -2300,12 +2321,6 @@ namespace Sunny.UI
             PageAdded?.Invoke(this, e);
         }
 
-        public event OnUIPageChanged PageSelected;
-        internal void DealPageSelected(object sender, UIPageEventArgs e)
-        {
-            PageSelected?.Invoke(this, e);
-        }
-
         public event OnUIPageChanged PageRemoved;
         internal void DealPageRemoved(object sender, UIPageEventArgs e)
         {

SunnyUI/Frames/IFrame.cs

@@ -59,6 +59,8 @@ namespace Sunny.UI
         T GetPage<T>() where T : UIPage;
 
         List<T> GetPages<T>() where T : UIPage;
+
+        UIPage SelectedPage { get; }
     }
 
     public class UIPageParamsArgs : EventArgs

SunnyUI/Frames/UIPage.cs

@@ -474,11 +474,9 @@ namespace Sunny.UI
             get; set;
         }
 
-        internal event OnUIPageChanged PageSelected;
         public virtual void Init()
         {
             Initialize?.Invoke(this, new EventArgs());
-            PageSelected?.Invoke(this, new UIPageEventArgs(this));
         }
 
         protected override void OnLoad(EventArgs e)