关于.net：WPF中鼠标下A型控件的计数

count controls of type A under the mouse in WPF

我在画布上有一些自定义的 A 面板，那里也有 B 面板，我如何计算 A 面板实际上位于鼠标光标处？

我知道这可以通过 VisualTreeHelper.HitTest 来实现，但是没有太多机会，它总是返回自定义面板上的元素或者什么都不返回…

这是我的代码

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.cs

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public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}

List<UserControl1> ucs = new List<UserControl1>();

private void Window_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
GetUcsCount(e);
Console.WriteLine("ucs.Count = {0}", ucs.Count);
}

private void GetUcsCount(MouseButtonEventArgs e)
{
ucs.Clear();

Point p = e.GetPosition(this);

VisualTreeHelper.HitTest(this, null,
new HitTestResultCallback(MyHitTestCallback),
new PointHitTestParameters(p));
}

HitTestResultBehavior MyHitTestCallback(HitTestResult result)
{
if (result.VisualHit.GetType() == typeof(UserControl1))
{
ucs.Add(result.VisualHit as UserControl1);
}

return HitTestResultBehavior.Continue;
}
}

result == 0 我点击的任何地方…

alt

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HitTestResultBehavior MyHitTestCallback(HitTestResult result)
{
DependencyObject visualHit = result.VisualHit;
UserControl1 parentUserControl = GetVisualParent<UserControl1>(visualHit);
if (parentUserControl != null && ucs.IndexOf(parentUserControl) < 0)
{
ucs.Add(parentUserControl as UserControl1);
}
return HitTestResultBehavior.Continue;
}
public static T GetVisualParent< T >(object childObject) where T : Visual
{
DependencyObject child = childObject as DependencyObject;
while ((child != null) && !(child is T))
{
child = VisualTreeHelper.GetParent(child);
}
return child as T;
}

原创文章，作者：ItWorker，如若转载，请注明出处：https://blog.ytso.com/269807.html

关于.net：WPF中鼠标下A型控件的计数

count controls of type A under the mouse in WPF

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