IRawElementProviderFragment.Navigate(NavigateDirection) 方法

定义

命名空间:

System.Windows.Automation.Provider

程序集:

UIAutomationProvider.dll

检索树中指定方向的UI 自动化元素。

public:
 System::Windows::Automation::Provider::IRawElementProviderFragment ^ Navigate(System::Windows::Automation::Provider::NavigateDirection direction);

public System.Windows.Automation.Provider.IRawElementProviderFragment Navigate (System.Windows.Automation.Provider.NavigateDirection direction);

abstract member Navigate : System.Windows.Automation.Provider.NavigateDirection -> System.Windows.Automation.Provider.IRawElementProviderFragment

Public Function Navigate (direction As NavigateDirection) As IRawElementProviderFragment

参数

direction

NavigateDirection

导航方向。

返回

IRawElementProviderFragment

指定方向的元素，或者 null 没有该方向的元素。

示例

以下示例代码演示具有单个子元素的 Navigate 片段根的实现。 由于实现元素是片段根，因此它不启用对父元素或同级元素的导航。

IRawElementProviderFragment IRawElementProviderFragment.Navigate(NavigateDirection direction)
{
    if ((direction == NavigateDirection.FirstChild)
        || (direction == NavigateDirection.LastChild)) 
    {
        // Return the provider that is the sole child of this one.
        return (IRawElementProviderFragment)ChildControl;
    }
    else
    {
        return null;
    };
}

Function Navigate(ByVal direction As NavigateDirection) As IRawElementProviderFragment _
    Implements IRawElementProviderFragment.Navigate

    If direction = NavigateDirection.FirstChild _
        OrElse direction = NavigateDirection.LastChild Then
        ' Return the provider that is the sole child of this one.
        Return CType(ChildControl, IRawElementProviderFragment)
    Else
        Return Nothing
    End If

End Function 'IRawElementProviderFragment.Navigate

以下示例演示一个实现，该片段表示列表框中的单个项。 在这种情况下，该元素允许导航到其父级和同级，但不能导航到任何子级。

/// <summary>
/// Navigate to adjacent elements in the automation tree.
/// </summary>
/// <param name="direction">Direction to navigate.</param>
/// <returns>The element in that direction, or null.</returns>
/// <remarks>
/// parentControl is the provider for the list box.
/// parentItems is the collection of list item providers.
/// </remarks>
public IRawElementProviderFragment Navigate(NavigateDirection direction)
{
    int myIndex = parentItems.IndexOf(this);
    if (direction == NavigateDirection.Parent)
    {
        return (IRawElementProviderFragment)parentControl;
    }
    else if (direction == NavigateDirection.NextSibling)
    {
        if (myIndex < parentItems.Count - 1)
        {
            return (IRawElementProviderFragment)parentItems[myIndex + 1];
        }
        else
        {
            return null;
        }
    }
    else if (direction == NavigateDirection.PreviousSibling)
    {
        if (myIndex > 0)
        {
            return (IRawElementProviderFragment)parentItems[myIndex - 1];
        }
        else
        {
            return null;
        }
    }
    else
    {
        return null;
    }
}

''' <summary>
''' Navigate to adjacent elements in the automation tree.
''' </summary>
''' <param name="direction">Direction to navigate.</param>
''' <returns>The element in that direction, or null.</returns>
''' <remarks>
''' parentControl is the provider for the list box.
''' parentItems is the collection of list item providers.
''' </remarks>
Public Function Navigate(ByVal direction As NavigateDirection) As IRawElementProviderFragment _
    Implements IRawElementProviderFragment.Navigate

    Dim myIndex As Integer = parentItems.IndexOf(Me)
    If direction = NavigateDirection.Parent Then
        Return DirectCast(parentControl, IRawElementProviderFragment)
    ElseIf direction = NavigateDirection.NextSibling Then
        If myIndex < parentItems.Count - 1 Then
            Return DirectCast(parentItems((myIndex + 1)), IRawElementProviderFragment)
        Else
            Return Nothing
        End If
    ElseIf direction = NavigateDirection.PreviousSibling Then
        If myIndex > 0 Then
            Return DirectCast(parentItems((myIndex - 1)), IRawElementProviderFragment)
        Else
            Return Nothing
        End If
    Else
        Return Nothing
    End If

End Function 'Navigate

注解

此方法UI 自动化服务器的实现定义UI 自动化元素树的结构。

导航必须向上支持到父级，向下到第一个和最后一个子级，以及横向到下一个和以前的同级，如适用。

每个子节点只有一个父节点，并且必须放置在从父 FirstChild 节点到达的同级链中 LastChild。

兄弟姐妹之间的关系必须双向相同：如果 A 是 B，PreviousSibling则 B 是 A。NextSibling A FirstChild 没有PreviousSibling，没有LastChildNextSibling。

片段根不支持导航到父级或同级;片段根之间的导航由默认窗口提供程序处理。 片段中的元素只能导航到该片段中的其他元素。

另请参阅

• 服务器端UI 自动化提供程序实现