SelectionItemPattern.AddToSelection Methode
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Hiermee voegt u het huidige element toe aan de verzameling geselecteerde items.
public:
void AddToSelection();
public void AddToSelection();
member this.AddToSelection : unit -> unit
Public Sub AddToSelection ()
Uitzonderingen
Er wordt geprobeerd een selectie toe te voegen aan een container met één selectie, waarbij CanSelectMultipleProperty = false en een ander element al is geselecteerd.
Voorbeelden
In het volgende voorbeeld ziet u hoe u een element toevoegt aan de verzameling geselecteerde items.
///--------------------------------------------------------------------
/// <summary>
/// Retrieves the selection container for a selection item.
/// </summary>
/// <param name="selectionItem">
/// An automation element that supports SelectionItemPattern.
/// </param>
///--------------------------------------------------------------------
private AutomationElement GetSelectionItemContainer(
AutomationElement selectionItem)
{
// Selection item cannot be null
if (selectionItem == null)
{
throw new ArgumentException();
}
SelectionItemPattern selectionItemPattern =
selectionItem.GetCurrentPattern(SelectionItemPattern.Pattern)
as SelectionItemPattern;
if (selectionItemPattern == null)
{
return null;
}
else
{
return selectionItemPattern.Current.SelectionContainer;
}
}
'''--------------------------------------------------------------------
''' <summary>
''' Retrieves the selection container for a selection item.
''' </summary>
''' <param name="selectionItem">
''' An automation element that supports SelectionItemPattern.
''' </param>
'''--------------------------------------------------------------------
Private Function GetSelectionItemContainer( _
ByVal selectionItem As AutomationElement) As AutomationElement
' Selection item cannot be null
If selectionItem Is Nothing Then
Throw New ArgumentException()
End If
Dim selectionItemPattern As SelectionItemPattern = _
DirectCast(selectionItem.GetCurrentPattern( _
selectionItemPattern.Pattern), SelectionItemPattern)
If selectionItemPattern Is Nothing Then
Return Nothing
Else
Return selectionItemPattern.Current.SelectionContainer
End If
End Function 'GetSelectionItemContainer
///--------------------------------------------------------------------
/// <summary>
/// Attempts to add the current item to a collection
/// of selected items.
/// </summary>
/// <param name="selectionItem">
/// An automation element that supports SelectionItemPattern.
/// </param>
///--------------------------------------------------------------------
private void AddItemToSelection(AutomationElement selectionItem)
{
if (selectionItem == null)
{
throw new ArgumentNullException(
"Argument cannot be null or empty.");
}
AutomationElement selectionContainer =
GetSelectionItemContainer(selectionItem);
// Selection container cannot be null
if (selectionContainer == null)
{
throw new ElementNotAvailableException();
}
SelectionPattern selectionPattern =
selectionContainer.GetCurrentPattern(SelectionPattern.Pattern)
as SelectionPattern;
if (selectionPattern == null)
{
return;
}
if (selectionPattern.Current.CanSelectMultiple)
{
SelectionItemPattern selectionItemPattern =
selectionItem.GetCurrentPattern(
SelectionItemPattern.Pattern)
as SelectionItemPattern;
if (selectionItemPattern != null)
{
try
{
selectionItemPattern.AddToSelection();
}
catch (InvalidOperationException)
{
// Unable to add to selection
return;
}
}
}
}
'''--------------------------------------------------------------------
''' <summary>
''' Attempts to add the current item to a collection
''' of selected items.
''' </summary>
''' <param name="selectionItem">
''' An automation element that supports SelectionItemPattern.
''' </param>
'''--------------------------------------------------------------------
Private Sub AddItemToSelection(ByVal selectionItem As AutomationElement)
If selectionItem Is Nothing Then
Throw New ArgumentNullException("Argument cannot be null or empty.")
End If
Dim selectionContainer As AutomationElement = _
GetSelectionItemContainer(selectionItem)
' Selection container cannot be null
If selectionContainer Is Nothing Then
Throw New ElementNotAvailableException()
End If
Dim selectionPattern As SelectionPattern = DirectCast( _
selectionContainer.GetCurrentPattern(selectionPattern.Pattern), _
SelectionPattern)
If selectionPattern Is Nothing Then
Return
End If
If selectionPattern.Current.CanSelectMultiple Then
Dim selectionItemPattern As SelectionItemPattern = DirectCast( _
selectionItem.GetCurrentPattern(selectionItemPattern.Pattern), _
SelectionItemPattern)
If Not (selectionItemPattern Is Nothing) Then
Try
selectionItemPattern.AddToSelection()
Catch
' Unable to add to selection
Return
End Try
End If
End If
End Sub