修复全屏窗口置顶失效问题

src/UI/Helpers/MainFormWinHelper.cs

@@ -136,6 +136,25 @@ public void ApplyRoundedCorners()
             catch { }
         }
 
+        // =================================================================
+        // 置顶守护
+        // =================================================================
+
+        /// <summary>
+        /// 通过 Win32 API 无条件强制置顶窗口。
+        /// 不检查 WS_EX_TOPMOST 标志，因为在全屏应用（如 VMware、无边框全屏游戏）中
+        /// 该标志可能仍然存在但窗口实际被覆盖，必须重新调用 SetWindowPos 才能恢复显示。
+        /// </summary>
+        public void ReapplyTopMost()
+        {
+            try
+            {
+                SetWindowPos(_form.Handle, HWND_TOPMOST, 0, 0, 0, 0,
+                    SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE);
+            }
+            catch { }
+        }
+
         // =================================================================
         // Win32 API
         // =================================================================
@@ -152,18 +171,24 @@ public static int RegisterTaskbarCreatedMessage()
         [DllImport("dwmapi.dll")] private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, ref int attrValue, int attrSize);
         [DllImport("user32.dll", SetLastError = true)] private static extern int GetWindowLong(IntPtr hWnd, int nIndex);
         [DllImport("user32.dll", SetLastError = true)] private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
+        [DllImport("user32.dll", SetLastError = true)] private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);
         [DllImport("user32.dll")] [return: MarshalAs(UnmanagedType.Bool)] public static extern bool SetForegroundWindow(IntPtr hWnd);
         [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)] public static extern int RegisterWindowMessage(string lpString);
         [DllImport("user32.dll", SetLastError = true)] public static extern bool ChangeWindowMessageFilter(uint message, uint dwFlag);
 
         public const uint MSGFLT_ADD = 1;
+        private static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
+        private const uint SWP_NOMOVE = 0x0002;
+        private const uint SWP_NOSIZE = 0x0001;
+        private const uint SWP_NOACTIVATE = 0x0010;
         private const int DWMWA_WINDOW_CORNER_PREFERENCE = 33;
         private const int DWMWCP_ROUND = 2;
         private const int DWMWA_BORDER_COLOR = 34;
         private const int DWMWA_COLOR_NONE = unchecked((int)0xFFFFFFFE);
         private const int GWL_EXSTYLE = -20;
         private const int WS_EX_TRANSPARENT = 0x20;
         private const int WS_EX_LAYERED = 0x80000;
+        private const int WS_EX_TOPMOST = 0x00000008;
 
         public static void ActivateWindow(IntPtr handle) => SetForegroundWindow(handle);
     }

src/UI/MainForm_Transparent.cs

@@ -25,6 +25,7 @@ public class MainForm : Form
 
         private Point _dragOffset;
         private bool _uiDragging = false;
+        private System.Windows.Forms.Timer? _topMostGuardTimer;
 
         // 防止 Win11 自动隐藏无边框 + 无任务栏窗口
         protected override CreateParams CreateParams
@@ -324,31 +325,41 @@ protected override void OnShown(EventArgs e)
             {
                  _ = _bizHelper.RunStartupChecksAsync();
             }
-            // [Fix] 强制置顶刷新，增加重试机制确保在某些系统环境下依然生效
-            if (_cfg.TopMost)
-            {
-                this.BeginInvoke(new Action(async () =>
-                {
-                    await Task.Delay(3000);
-                    // 1. 立即执行第一次置顶
-                    this.TopMost = false;
-                    await Task.Delay(1000);
-                    this.TopMost = true;
-                    this.BringToFront();
-                }));
-            }
+            // [Fix] 置顶守护：周期性检测并恢复被虚拟桌面切换、全屏游戏等夺走的置顶状态
+            StartTopMostGuard();
         }
 
         protected override void OnFormClosed(FormClosedEventArgs e)
         {
-            _cfg.Save(); 
-            TrafficLogger.Save(); 
+            _topMostGuardTimer?.Stop();
+            _topMostGuardTimer?.Dispose();
+            _cfg.Save();
+            TrafficLogger.Save();
             src.WebServer.LiteWebServer.Instance?.Stop();
-            
+
             base.OnFormClosed(e);
-            
+
             _ui?.Dispose();
             _bizHelper.Dispose();
         }
+
+        private void StartTopMostGuard()
+        {
+            if (_topMostGuardTimer != null) return;
+            _topMostGuardTimer = new System.Windows.Forms.Timer { Interval = 3000 };
+            _topMostGuardTimer.Tick += (_, __) =>
+            {
+                if (_cfg.TopMost && Visible)
+                {
+                    // 如果本应用有其他活动窗口（如设置面板），跳过强制置顶以免遮挡
+                    var activeForm = Form.ActiveForm;
+                    if (activeForm != null && activeForm != this)
+                        return;
+
+                    _winHelper.ReapplyTopMost();
+                }
+            };
+            _topMostGuardTimer.Start();
+        }
     }
 }