AutomationInteropProvider.RaiseStructureChangedEvent 方法

  • 参考

定义

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

当 UI 自动化树发生更改时引发 事件。

public:
 static void RaiseStructureChangedEvent(System::Windows::Automation::Provider::IRawElementProviderSimple ^ provider, System::Windows::Automation::StructureChangedEventArgs ^ e);
public static void RaiseStructureChangedEvent (System.Windows.Automation.Provider.IRawElementProviderSimple provider, System.Windows.Automation.StructureChangedEventArgs e);
static member RaiseStructureChangedEvent : System.Windows.Automation.Provider.IRawElementProviderSimple * System.Windows.Automation.StructureChangedEventArgs -> unit
Public Shared Sub RaiseStructureChangedEvent (provider As IRawElementProviderSimple, e As StructureChangedEventArgs)

参数

provider
IRawElementProviderSimple

与该事件关联的元素。

e
StructureChangedEventArgs

有关事件的信息。

示例

以下示例演示如何在向自定义列表框添加或从中删除子级时引发事件。

/// <summary>
/// Responds to an addition to the UI Automation tree structure by raising an event.
/// </summary>
/// <param name="list">
/// The list to which the item was added.
/// </param>
/// <remarks>
/// For the runtime Id of the item, pass 0 because the provider cannot know
/// what its actual runtime Id is.
/// </remarks>
public static void OnStructureChangeAdd(CustomListControl list)
{
    if (AutomationInteropProvider.ClientsAreListening)
    {
        int[] fakeRuntimeId = { 0 };
        StructureChangedEventArgs args =
            new StructureChangedEventArgs(StructureChangeType.ChildrenBulkAdded, 
            fakeRuntimeId);
        AutomationInteropProvider.RaiseStructureChangedEvent(
            (IRawElementProviderSimple)list.Provider, args);
    }
}

/// <summary>
/// Responds to a removal from the UI Automation tree structure 
/// by raising an event.
/// </summary>
/// <param name="list">
/// The list from which the item was removed.
/// </param>
/// <remarks>
/// For the runtime Id of the list, pass 0 because the provider cannot know
/// what its actual runtime ID is.
/// </remarks>
public static void OnStructureChangeRemove(CustomListControl list)
{
    if (AutomationInteropProvider.ClientsAreListening)
    {
        int[] fakeRuntimeId = { 0 };
        StructureChangedEventArgs args =
            new StructureChangedEventArgs(StructureChangeType.ChildrenBulkRemoved, 
            fakeRuntimeId);
        AutomationInteropProvider.RaiseStructureChangedEvent(
            (IRawElementProviderSimple)list.Provider, args);
    }
}

''' <summary>
''' Responds to an addition to the UI Automation tree structure by raising an event.
''' </summary>
''' <param name="list">
''' The list to which the item was added.
''' </param>
''' <remarks>
''' For the runtime Id of the item, pass 0 because the provider cannot know
''' what its actual runtime Id is.
''' </remarks>
Public Shared Sub OnStructureChangeAdd(ByVal list As CustomListControl)
    If AutomationInteropProvider.ClientsAreListening Then
        Dim fakeRuntimeId(1) As Integer
        fakeRuntimeId(0) = 0
        Dim args As New StructureChangedEventArgs( _
            StructureChangeType.ChildrenBulkAdded, fakeRuntimeId)
        AutomationInteropProvider.RaiseStructureChangedEvent( _
            CType(list.Provider, IRawElementProviderSimple), args)
    End If

End Sub


''' <summary>
''' Responds to a removal from the UI Automation tree structure by raising an event.
''' </summary>
''' <param name="list">
''' The list from which the item was removed.
''' </param>
''' <remarks>
''' For the runtime Id of the list, pass 0 because the provider cannot know
''' what its actual runtime ID is.
''' </remarks>
Public Shared Sub OnStructureChangeRemove(ByVal list As CustomListControl)
    If AutomationInteropProvider.ClientsAreListening Then
        Dim fakeRuntimeId(1) As Integer
        fakeRuntimeId(0) = 0
        Dim args As New StructureChangedEventArgs( _
            StructureChangeType.ChildrenBulkRemoved, fakeRuntimeId)
        AutomationInteropProvider.RaiseStructureChangedEvent( _
            CType(list.Provider, IRawElementProviderSimple), args)
    End If

End Sub

注解

树结构更改的一个示例是在列表框中添加或删除子元素，或者在树视图中展开或折叠子元素。

删除子元素时，元素或其容器的运行时标识符将 StructureChangedEventArgs 传递给构造函数。 但是，在当前版本的 UI 自动化中，提供程序的实例无法轻松发现其运行时标识符。 方法 GetRuntimeId 通常返回包含 AppendRuntimeId的数组，这是一个幻数，指示 UI 自动化系统为每个控件实例创建唯一的标识符。 不应在事件中使用 提供 GetRuntimeId 的原始值，因为它对客户端毫无意义，并且不能用于标识特定实例。

由于此限制，和 ChildRemoved 类型的ChildAdded事件不是很有用。 作为替代方法，请始终使用 ChildrenBulkAdded 和 ChildrenBulkRemoved，传递 0 作为运行时标识符。 不能使用 null，因为这会引发异常。 客户端将收到有关已在容器中进行了更改的通知， (由 sender 传递给 StructureChangedEventHandler) 的参数标识，而不会具体通知已添加或删除哪些子项。

适用于

另请参阅