* UIMainFrame：页面框架增加Selecting事件，在页面切换时执行该事件

SunnyUI.Demo/FMain.Designer.cs

@@ -93,6 +93,7 @@
             this.uiAvatar.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
             this.uiAvatar.Font = new System.Drawing.Font("微软雅黑", 12F);
             this.uiAvatar.Location = new System.Drawing.Point(939, 25);
+            this.uiAvatar.MinimumSize = new System.Drawing.Size(1, 1);
             this.uiAvatar.Name = "uiAvatar";
             this.uiAvatar.Size = new System.Drawing.Size(66, 70);
             this.uiAvatar.TabIndex = 4;
@@ -110,6 +111,7 @@
             this.ShowRadius = false;
             this.ShowShadow = true;
             this.Text = "SunnyUI.Net";
+            this.Selecting += new Sunny.UI.UIMainFrame.OnSelecting(this.FMain_Selecting);
             this.Header.ResumeLayout(false);
             this.ResumeLayout(false);
 

SunnyUI.Demo/FMain.cs

@@ -87,5 +87,10 @@ namespace Sunny.UI.Demo
         {
             state.ConsoleWriteLine("WindowState");
         }
+
+        private void FMain_Selecting(object sender, TabControlCancelEventArgs e, UIPage page)
+        {
+            page?.Text.ConsoleWriteLine();
+        }
     }
 }

SunnyUI/Frames/UIMainFrame.Designer.cs

@@ -48,6 +48,7 @@
             this.MainContainer.Size = new System.Drawing.Size(800, 415);
             this.MainContainer.SizeMode = System.Windows.Forms.TabSizeMode.Fixed;
             this.MainContainer.TabIndex = 0;
+            this.MainContainer.Selecting += new System.Windows.Forms.TabControlCancelEventHandler(this.MainContainer_Selecting);
             // 
             // tabPage1
             // 
@@ -63,7 +64,7 @@
             this.tabPage2.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(235)))), ((int)(((byte)(243)))), ((int)(((byte)(255)))));
             this.tabPage2.Location = new System.Drawing.Point(0, 40);
             this.tabPage2.Name = "tabPage2";
-            this.tabPage2.Size = new System.Drawing.Size(800, 375);
+            this.tabPage2.Size = new System.Drawing.Size(450, 230);
             this.tabPage2.TabIndex = 1;
             this.tabPage2.Text = "tabPage2";
             // 

SunnyUI/Frames/UIMainFrame.cs

@@ -20,7 +20,9 @@
 ******************************************************************************/
 
 using System;
+using System.Collections.Generic;
 using System.ComponentModel;
+using System.Windows.Forms;
 
 namespace Sunny.UI
 {
@@ -31,6 +33,7 @@ namespace Sunny.UI
             InitializeComponent();
             MainContainer.TabVisible = false;
             MainContainer.BringToFront();
+            MainContainer.TabPages.Clear();
         }
 
         protected override void OnShown(EventArgs e)
@@ -83,5 +86,19 @@ namespace Sunny.UI
             get => MainContainer.ShowActiveCloseButton;
             set => MainContainer.ShowActiveCloseButton = value;
         }
+
+        private void MainContainer_Selecting(object sender, TabControlCancelEventArgs e)
+        {
+            if (Selecting != null)
+            {
+                List<UIPage> pages = e.TabPage.GetControls<UIPage>();
+                Selecting?.Invoke(this, e, pages.Count == 0 ? null : pages[0]);
+            }
+        }
+
+        public delegate void OnSelecting(object sender, TabControlCancelEventArgs e, UIPage page);
+
+        [Description("页面选择事件"), Category("SunnyUI")]
+        public event OnSelecting Selecting;
     }
 }