通过

IRawElementProviderFragmentRoot.ElementProviderFromPoint 方法

  • 参考

定义

命名空间:
System.Windows.Automation.Provider
程序集:
UIAutomationProvider.dll

检索此片段中位于指定点处的元素。

public:
 System::Windows::Automation::Provider::IRawElementProviderFragment ^ ElementProviderFromPoint(double x, double y);
public System.Windows.Automation.Provider.IRawElementProviderFragment ElementProviderFromPoint (double x, double y);
abstract member ElementProviderFromPoint : double * double -> System.Windows.Automation.Provider.IRawElementProviderFragment
Public Function ElementProviderFromPoint (x As Double, y As Double) As IRawElementProviderFragment

参数

x
Double

X 坐标。

y
Double

Y 坐标。

返回

IRawElementProviderFragment

位于指定点处的子元素的提供程序（如果存在），或者根提供程序（如果该点位于此元素上，而不是位于任何子元素上）。 否则返回 null。

示例

下面的代码示例演示了非滚动列表框此方法的一个可能实现。 列表项在指定点的索引是使用每个项的高度计算的，此时返回的项。 例如，如果该点不存在项 (，则它是列表框的空白区域，该方法将返回 null 引用 (Nothing) 。

delegate Rectangle MyDelegate(Rectangle clientRect);

/// <summary>
/// Gets the child element that is at the specified point.
/// </summary>
/// <param name="x">Distance from the left of the application window.</param>
/// <param name="y">Distance from the top of the application window.</param>
/// <returns>The provider for the element at that point.</returns>
IRawElementProviderFragment IRawElementProviderFragmentRoot.ElementProviderFromPoint(
    double x, double y)
{
    // The RectangleToScreen method on the control can't be called directly from 
    // this thread, so use delegation.
    MyDelegate del = new MyDelegate(this.RectangleToScreen);
    Rectangle screenRectangle = (Rectangle)this.Invoke(del, new object[] { this.DisplayRectangle });

    if (screenRectangle.Contains((int)x, (int)y))
    {
        int index = (int)(((int)(y - screenRectangle.Y)) / itemHeight);
        if (index < myItems.Count)
        {
            return (IRawElementProviderFragment)myItems[index];
        }
        else
        {
            return (IRawElementProviderFragment)this;
        }
    }
    else
    {
        return null;
    }
}

Delegate Function MyDelegate(ByVal clientRect As Rectangle) As Rectangle

''' <summary>
''' Gets the child element that is at the specified point.
''' </summary>
''' <param name="x">Distance from the left of the application window.</param>
''' <param name="y">Distance from the top of the application window.</param>
''' <returns>The provider for the element at that point.</returns>
Function ElementProviderFromPoint(ByVal x As Double, ByVal y As Double) As IRawElementProviderFragment _
    Implements IRawElementProviderFragmentRoot.ElementProviderFromPoint

    Dim pointX As Integer = CInt(x)
    Dim pointY As Integer = CInt(y)

    ' The RectangleToScreen method on the control can't be called directly from 
    ' this thread, so use delegation.
    Dim converterDelegate As MyDelegate = New MyDelegate(AddressOf Me.RectangleToScreen)
    Dim screenRectangle As Rectangle = DirectCast(Me.Invoke(converterDelegate, _
        New Object() {Me.DisplayRectangle}), Rectangle)
    If screenRectangle.Contains(pointX, pointY) Then
        Dim index As Integer = CInt((pointY - screenRectangle.Y) \ itemHeight)
        If index < myItems.Count Then
            Return DirectCast(myItems(index), IRawElementProviderFragment)
        Else
            Return DirectCast(Me, IRawElementProviderFragment)
        End If
    Else
        Return Nothing
    End If
End Function

注解

如果点位于此片段托管的另一个框架中的元素上，该方法将返回承载该片段的元素。

返回的提供程序应对应于将在指定点接收鼠标输入的元素。

适用于

另请参阅