GeometryHitTestParameters 类

定义

public ref class GeometryHitTestParameters : System::Windows::Media::HitTestParameters

public class GeometryHitTestParameters : System.Windows.Media.HitTestParameters

type GeometryHitTestParameters = class
    inherit HitTestParameters

Public Class GeometryHitTestParameters
Inherits HitTestParameters

继承

Object

HitTestParameters

GeometryHitTestParameters

示例

以下示例演示如何使用GeometryHitTestParametersHitTest该方法设置命中测试。 Point传递给OnMouseDown该方法的值用于创建Geometry对象，以便扩展命中测试的范围。

// Respond to the mouse button down event by setting up a hit test results callback.
private void OnMouseDown(object sender, MouseButtonEventArgs e)
{
    // Retrieve the coordinate of the mouse position.
    Point pt = e.GetPosition((UIElement)sender);

    // Expand the hit test area by creating a geometry centered on the hit test point.
    EllipseGeometry expandedHitTestArea = new EllipseGeometry(pt, 10.0, 10.0);

    // Clear the contents of the list used for hit test results.
    hitResultsList.Clear();

    // Set up a callback to receive the hit test result enumeration.
    VisualTreeHelper.HitTest(myControl, null,
        new HitTestResultCallback(MyHitTestResultCallback),
        new GeometryHitTestParameters(expandedHitTestArea));

    // Perform actions on the hit test results list.
    if (hitResultsList.Count > 0)
    {
        ProcessHitTestResultsList();
    }
}

' Respond to the mouse button down event by setting up a hit test results callback.
Private Overloads Sub OnMouseDown(ByVal sender As Object, ByVal e As MouseButtonEventArgs)
    ' Retrieve the coordinate of the mouse position.
    Dim pt As Point = e.GetPosition(CType(sender, UIElement))

    ' Expand the hit test area by creating a geometry centered on the hit test point.
    Dim expandedHitTestArea As New EllipseGeometry(pt, 10.0, 10.0)

    ' Clear the contents of the list used for hit test results.
    hitResultsList.Clear()

    ' Set up a callback to receive the hit test result enumeration.
    VisualTreeHelper.HitTest(myControl, Nothing, New HitTestResultCallback(AddressOf MyHitTestResultCallback), New GeometryHitTestParameters(expandedHitTestArea))

    ' Perform actions on the hit test results list.
    If hitResultsList.Count > 0 Then
        ProcessHitTestResultsList()
    End If
End Sub

该 IntersectionDetail 属性 GeometryHitTestResult 提供有关使用 Geometry 命中测试参数的命中测试结果的信息。 下图显示了命中测试几何图形 (蓝色圆) 与目标对象 (红方) 之间的关系。

命中测试几何图形和目标对象之间的交集

注解

使用 GeometryHitTestParameters 类，可以使用值 Geometry 进行测试，以确定任何视觉对象是否与 Geometry 值相交。

还可以通过创建PointHitTestParameters对象来命中测试Point值。

构造函数

属性

方法

适用于