add function codes

src/Shared/HandyControl_Shared/Tools/Helper/VisualHelper.cs

@@ -3,6 +3,7 @@ using System.Linq;
 using System.Windows;
 using System.Windows.Interop;
 using System.Windows.Media;
+using HandyControl.Tools.Interop;
 
 namespace HandyControl.Tools
 {
@@ -11,10 +12,7 @@ namespace HandyControl.Tools
         internal static VisualStateGroup TryGetVisualStateGroup(DependencyObject d, string groupName)
         {
             var root = GetImplementationRoot(d);
-            if (root == null)
-            {
-                return null;
-            }
+            if (root == null) return null;
 
             return VisualStateManager
                 .GetVisualStateGroups(root)?
@@ -31,10 +29,7 @@ namespace HandyControl.Tools
 
         public static T GetChild<T>(DependencyObject d) where T : DependencyObject
         {
-            if (d is T t)
-            {
-                return t;
-            }
+            if (d is T t) return t;
 
             for (var i = 0; i < VisualTreeHelper.GetChildrenCount(d); i++)
             {
@@ -47,7 +42,34 @@ namespace HandyControl.Tools
             return default;
         }
 
-        public static IntPtr GetHandle(this Visual visual) =>
-            (PresentationSource.FromVisual(visual) as HwndSource)?.Handle ?? IntPtr.Zero;
+        public static IntPtr GetHandle(this Visual visual)
+        {
+            return (PresentationSource.FromVisual(visual) as HwndSource)?.Handle ?? IntPtr.Zero;
+        }
+
+        internal static void HitTestVisibleElements(Visual visual, HitTestResultCallback resultCallback,
+            HitTestParameters parameters)
+        {
+            VisualTreeHelper.HitTest(visual, ExcludeNonVisualElements, resultCallback, parameters);
+        }
+
+        private static HitTestFilterBehavior ExcludeNonVisualElements(DependencyObject potentialHitTestTarget)
+        {
+            if (!(potentialHitTestTarget is Visual)) return HitTestFilterBehavior.ContinueSkipSelfAndChildren;
+
+            if (!(potentialHitTestTarget is UIElement uIElement) || uIElement.IsVisible && uIElement.IsEnabled)
+                return HitTestFilterBehavior.Continue;
+
+            return HitTestFilterBehavior.ContinueSkipSelfAndChildren;
+        }
+
+        internal static bool ModifyStyle(IntPtr hWnd, int styleToRemove, int styleToAdd)
+        {
+            var windowLong = InteropMethods.GetWindowLong(hWnd, InteropValues.GWL.STYLE);
+            var num = (windowLong & ~styleToRemove) | styleToAdd;
+            if (num == windowLong) return false;
+            InteropMethods.SetWindowLong(hWnd, InteropValues.GWL.STYLE, num);
+            return true;
+        }
     }
 }