improve:窗口无焦点

Ink Canvas/MainWindow.xaml.cs

@@ -35,6 +35,14 @@ namespace Ink_Canvas {
         private static extern int GetWindowLong(IntPtr hWnd, int nIndex);
         private const int GWL_EXSTYLE = -20;
         private const int WS_EX_NOACTIVATE = 0x08000000;
+        [DllImport("user32.dll")]
+        private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);
+        private static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
+        private static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);
+        private const uint SWP_NOSIZE = 0x0001;
+        private const uint SWP_NOMOVE = 0x0002;
+        private const uint SWP_NOACTIVATE = 0x0010;
+        private const uint SWP_SHOWWINDOW = 0x0040;
         
         // 新增：设置窗口置顶并兼容无焦点
         private void SetTopmostWithNoActivate(bool topmost)
@@ -45,6 +53,15 @@ namespace Ink_Canvas {
             SetWindowLong(hwnd, GWL_EXSTYLE, exStyle & ~WS_EX_NOACTIVATE);
             // 设置 Topmost
             this.Topmost = topmost;
+            // 使用SetWindowPos确保无焦点置顶
+            if (topmost)
+            {
+                SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE | SWP_SHOWWINDOW);
+            }
+            else
+            {
+                SetWindowPos(hwnd, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE | SWP_SHOWWINDOW);
+            }
             // 再加回 WS_EX_NOACTIVATE
             exStyle = GetWindowLong(hwnd, GWL_EXSTYLE);
             SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_NOACTIVATE);