StructureChangedEventArgs(StructureChangeType, Int32[]) Constructor

Definition

Namespace:

System.Windows.Automation

Assembly:

UIAutomationTypes.dll

Initializes a new instance of the StructureChangeType class, specifying the type of change and the identifier (ID) of the element whose structure changed.

public:
 StructureChangedEventArgs(System::Windows::Automation::StructureChangeType structureChangeType, cli::array <int> ^ runtimeId);

public StructureChangedEventArgs (System.Windows.Automation.StructureChangeType structureChangeType, int[] runtimeId);

new System.Windows.Automation.StructureChangedEventArgs : System.Windows.Automation.StructureChangeType * int[] -> System.Windows.Automation.StructureChangedEventArgs

Public Sub New (structureChangeType As StructureChangeType, runtimeId As Integer())

Parameters

structureChangeType

StructureChangeType

A single value that specifies the type of change.

runtimeId

Int32[]

The runtime identifier (ID) of the UI Automation element whose structure changed.

Examples

The following example shows how to construct and raise an event when children are added to, or removed from, a custom list box.

/// <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

Remarks

The values that can be returned in structureChangeType depend on the implementation of the UI Automation provider. For example, when items are added to or removed from a Win32 list box, if the provider is not able to determine the number of items added or removed, it might specify ChildrenInvalidated and not ChildAdded or ChildRemoved.

The following table describes the information in the event received by the StructureChangedEventHandler for different structure changes.

structureChangeType	Event source	runtimeId
ChildAdded	The child that was added.	The child that was added.
ChildRemoved	The parent of the child that was removed.	The child that was removed.
ChildrenBulkAdded	The parent of the children that were added.	The parent of the children that were added.
ChildrenBulkRemoved	The parent of the children that were removed.	The parent of the children that were removed.
ChildrenInvalidated	The parent of the children that were invalidated.	The parent of the children that were invalidated

Custom controls might not be able to provide a meaningful value in runtimeId. For more information, see RaiseStructureChangedEvent.

See also

• RuntimeIdProperty