GridPattern.GetItem(Int32, Int32) Método

Definición

Espacio de nombres:

System.Windows.Automation

Ensamblado:

UIAutomationClient.dll

Recupera un AutomationElement que representa la celda especificada.

public:
 System::Windows::Automation::AutomationElement ^ GetItem(int row, int column);

public System.Windows.Automation.AutomationElement GetItem (int row, int column);

member this.GetItem : int * int -> System.Windows.Automation.AutomationElement

Public Function GetItem (row As Integer, column As Integer) As AutomationElement

Parámetros

row

Int32

Número ordinal de la fila de interés.

column

Int32

Número ordinal de la columna de interés.

Devoluciones

AutomationElement

Un AutomationElement que representa la celda recuperada.

Excepciones

ArgumentOutOfRangeException

La coordenada de fila o columna solicitada es menor que cero.

o bien

La coordenada de la fila solicitada es mayor que RowCount o la coordenada de la columna es mayor que ColumnCount.

Ejemplos

En el ejemplo siguiente, se declara un AutomationFocusChangedEvent agente de escucha para realizar un seguimiento del recorrido de los elementos de cuadrícula dentro de un contenedor de cuadrícula. Las propiedades del elemento se repiten en la consola en cada evento de cambio de foco.

///--------------------------------------------------------------------
/// <summary>
/// Set up grid item event listeners.
/// </summary>
/// <param name="targetControl">
/// The grid item container of interest.
/// </param>
///--------------------------------------------------------------------
private void SetGridItemEventListeners(AutomationElement targetControl)
{
    AutomationFocusChangedEventHandler gridItemFocusChangedListener =
        new AutomationFocusChangedEventHandler(OnGridItemFocusChange);
    Automation.AddAutomationFocusChangedEventHandler(
        gridItemFocusChangedListener);
}

'''--------------------------------------------------------------------
''' <summary>
''' Set up grid item event listeners.
''' </summary>
''' <param name="targetControl">
''' The grid item container of interest.
''' </param>
'''--------------------------------------------------------------------
Private Sub SetGridItemEventListeners( _
ByVal targetControl As AutomationElement)
    Dim gridItemFocusChangedListener As AutomationFocusChangedEventHandler = _
    AddressOf OnGridItemFocusChange
    Automation.AddAutomationFocusChangedEventHandler( _
    gridItemFocusChangedListener)
End Sub

///--------------------------------------------------------------------
/// <summary>
/// Event handler for grid item focus change.
/// Can be used to track traversal of individual grid items 
/// within a grid.
/// </summary>
/// <param name="src">Object that raised the event.</param>
/// <param name="e">Event arguments.</param>
///--------------------------------------------------------------------
private void OnGridItemFocusChange(
    object src, AutomationFocusChangedEventArgs e)
{
    // Make sure the element still exists. Elements such as tooltips
    // can disappear before the event is processed.
    AutomationElement sourceElement;
    try
    {
        sourceElement = src as AutomationElement;
    }
    catch (ElementNotAvailableException)
    {
        return;
    }

    // Gets a GridItemPattern from the source of the event.
    GridItemPattern gridItemPattern = 
        GetGridItemPattern(sourceElement);

    if (gridItemPattern == null)
    {
        return;
    }

    // Gets a GridPattern from the grid container.
    GridPattern gridPattern = 
        GetGridPattern(gridItemPattern.Current.ContainingGrid);

    if (gridPattern == null)
    {
        return;
    }

    AutomationElement gridItem = null;
    try
    {
        gridItem = gridPattern.GetItem(
        gridItemPattern.Current.Row, 
        gridItemPattern.Current.Column);
    }
    catch (ArgumentOutOfRangeException)
    {
        // If the requested row coordinate is larger than the RowCount 
        // or the column coordinate is larger than the ColumnCount.
        // -- OR --
        // If either of the requested row or column coordinates 
        // are less than zero.
        // TO DO: error handling.
    }

    // Further event processing can be done at this point.
    // For the purposes of this sample we just report item properties.
    StringBuilder gridItemReport = new StringBuilder();
    gridItemReport.AppendLine(
        gridItemPattern.Current.Row.ToString()).AppendLine(
        gridItemPattern.Current.Column.ToString()).AppendLine(
        gridItemPattern.Current.RowSpan.ToString()).AppendLine(
        gridItemPattern.Current.ColumnSpan.ToString()).AppendLine(
        gridItem.Current.AutomationId.ToString());
    Console.WriteLine(gridItemReport.ToString());
}

///--------------------------------------------------------------------
/// <summary>
/// Handles our application shutdown.
/// </summary>
/// <param name="args">Event arguments.</param>
///--------------------------------------------------------------------
protected override void OnExit(System.Windows.ExitEventArgs args)
{
    Automation.RemoveAllEventHandlers();
    base.OnExit(args);
}

'''--------------------------------------------------------------------
''' <summary>
''' Event handler for grid item focus change.
''' Can be used to track traversal of individual grid items 
''' within a grid.
''' </summary>
''' <param name="src">Object that raised the event.</param>
''' <param name="e">Event arguments.</param>
'''--------------------------------------------------------------------
Private Sub OnGridItemFocusChange( _
ByVal src As Object, ByVal e As AutomationFocusChangedEventArgs)
    ' Make sure the element still exists. Elements such as tooltips
    ' can disappear before the event is processed.
    Dim sourceElement As AutomationElement
    Try
        sourceElement = DirectCast(src, AutomationElement)
    Catch exc As ElementNotAvailableException
        Return
    End Try

    ' Gets a GridItemPattern from the source of the event.
    Dim gridItemPattern As GridItemPattern = _
    GetGridItemPattern(sourceElement)

    If gridItemPattern Is Nothing Then
        Return
    End If

    ' Gets a GridPattern from the grid container.
    Dim gridPattern As GridPattern = _
    GetGridPattern(gridItemPattern.Current.ContainingGrid)

    If gridPattern Is Nothing Then
        Return
    End If

    Dim gridItem As AutomationElement = Nothing
    Try
        gridItem = gridPattern.GetItem( _
        gridItemPattern.Current.Row, gridItemPattern.Current.Column)
    Catch
        ' If the requested row coordinate is larger than the RowCount 
        ' or the column coordinate is larger than the ColumnCount.
        ' -- OR --
        ' If either of the requested row or column coordinates 
        ' are less than zero.
        ' TO DO: error handling.
    End Try

    ' Further event processing can be done at this point.
    ' For the purposes of this sample we just report item properties.
    Dim gridItemReport As New StringBuilder()
    gridItemReport.AppendLine( _
    gridItemPattern.Current.Row.ToString()).AppendLine( _
    gridItemPattern.Current.Column.ToString()).AppendLine( _
    gridItemPattern.Current.RowSpan.ToString()).AppendLine( _
    gridItemPattern.Current.ColumnSpan.ToString()).AppendLine( _
    gridItem.Current.AutomationId.ToString())
    Console.WriteLine(gridItemReport.ToString())

End Sub


'''--------------------------------------------------------------------
''' <summary>
''' Handles our application shutdown.
''' </summary>
''' <param name="args">Event arguments.</param>
'''--------------------------------------------------------------------
Protected Overrides Sub OnExit(ByVal args As System.Windows.ExitEventArgs) 
    Automation.RemoveAllEventHandlers()
    MyBase.OnExit(args)

End Sub

Comentarios

Las coordenadas de cuadrícula se basan en cero con la esquina superior izquierda (o la celda superior derecha según la configuración regional) que tienen coordenadas (0,0).

Si una celda está vacía, se sigue devolviendo un elemento de automatización de la interfaz de usuario para admitir la recuperación de la ContainingGrid propiedad para esa celda. Esto es posible cuando el diseño de los elementos secundarios de la cuadrícula es similar a una matriz desigual, como se muestra aquí.

Ejemplo de un control Grid con coordenadas vacías