GridItemPattern.GridItemPatternInformation.ContainingGrid Property

Definition

Gets a UI Automation element that supports GridPattern and represents the container of the cell or item.

public System.Windows.Automation.AutomationElement ContainingGrid { get; }

Property Value

A UI Automation element that supports the GridPattern and represents the table cell or item container. The default is a null reference (Nothing in Microsoft Visual Basic .NET).

Examples

In the following example, an AutomationFocusChangedEvent listener is declared to track the traversal of grid items within a grid container. Item properties are echoed to the console upon each focus-changed event.

///--------------------------------------------------------------------
/// <summary>
/// Obtains a GridItemPattern control pattern from an 
/// automation element.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <returns>
/// A GridItemPattern object.
/// </returns>
///--------------------------------------------------------------------
private GridItemPattern GetGridItemPattern(
    AutomationElement targetControl)
{
    GridItemPattern gridItemPattern = null;

    try
    {
        gridItemPattern =
            targetControl.GetCurrentPattern(
            GridItemPattern.Pattern)
            as GridItemPattern;
    }
    // Object doesn't support the 
    // GridPattern control pattern
    catch (InvalidOperationException)
    {
        return null;
    }

    return gridItemPattern;
}
///--------------------------------------------------------------------
/// <summary>
/// Obtains a GridPattern control pattern from an 
/// automation element.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <returns>
/// A GridPattern object.
/// </returns>
///--------------------------------------------------------------------
private GridPattern GetGridPattern(
    AutomationElement targetControl)
{
    GridPattern gridPattern = null;

    try
    {
        gridPattern =
            targetControl.GetCurrentPattern(
            GridPattern.Pattern)
            as GridPattern;
    }
    // Object doesn't support the 
    // GridPattern control pattern
    catch (InvalidOperationException)
    {
        return null;
    }

    return gridPattern;
}
///--------------------------------------------------------------------
/// <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>
/// 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);
}

Applies to

Produk Versi
.NET Framework 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9