Exponer el contenido de una tabla mediante UI Automation
.gif "Nota") Nota |
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Esta documentación está dirigida a desarrolladores de .NET Framework que desean usar las clases administradas de UI Automation definidas en el espacio de nombres System.Windows.Automation.Para obtener información actualizada sobre UI Automation, vea Windows Automation API: UI Automation. |
En este tema se muestra cómo la Microsoft UI Automation se puede usar para exponer el contenido y las propiedades intrínsecas de cada celda en un control tabular.
Ejemplo
En el ejemplo de código siguiente se muestra cómo obtener un objeto AutomationElement que representa el contenido de una celda de tabla; también se obtienen propiedades de celda como los índices de fila y columna, los intervalos de fila y columna e información de encabezado de fila y columna. En el ejemplo se usa un controlador de evento de cambio de foco para simular el recorrido de teclado de un control tabular que implementa la UI Automation. La información para cada elemento de la tabla se expone en un evento de cambio de foco.
| Nota |
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Puesto que los cambios de foco son eventos de escritorio globales, deberían filtrarse los eventos de cambio de foco fuera de la tabla.En TrackFocus Sample encontrará una implementación relacionada. |
''' -------------------------------------------------------------------
''' <summary>
''' Starts the target application and returns the AutomationElement
''' obtained from the targets window handle.
''' </summary>
''' <param name="exe">
''' The target application.
''' </param>
''' <param name="filename">
''' The text file to be opened in the target application
''' </param>
''' <returns>
''' An AutomationElement representing the target application.
''' </returns>
''' -------------------------------------------------------------------
Private Function StartTarget(ByVal exe As String, ByVal filename As String) As AutomationElement
' Start text editor and load with a text file.
Dim p As Process = Process.Start(exe, filename)
' targetApp --> the root AutomationElement
Dim targetApp As AutomationElement = _
AutomationElement.FromHandle(p.MainWindowHandle)
Return targetApp
End Function
...
''' -------------------------------------------------------------------
''' <summary>
''' Obtain the table control of interest from the target application.
''' </summary>
''' <param name="targetApp">
''' The target application.
''' </param>
''' <returns>
''' An AutomationElement representing a table control.
''' </returns>
''' -------------------------------------------------------------------
Private Function GetTableElement(ByVal targetApp As AutomationElement) As AutomationElement
' The control type we're looking for; in this case 'Document'
Dim cond1 As PropertyCondition = _
New PropertyCondition( _
AutomationElement.ControlTypeProperty, _
ControlType.Table)
' The control pattern of interest; in this case 'TextPattern'.
Dim cond2 As PropertyCondition = _
New PropertyCondition( _
AutomationElement.IsTablePatternAvailableProperty, _
True)
Dim tableCondition As AndCondition = New AndCondition(cond1, cond2)
Dim targetTableElement As AutomationElement = _
targetApp.FindFirst(TreeScope.Descendants, tableCondition)
' If targetTableElement is null then a suitable table control
' was not found.
Return targetTableElement
End Function
...
'''--------------------------------------------------------------------
''' <summary>
''' Obtains a TableItemPattern control pattern from an
''' AutomationElement.
''' </summary>
''' <param name="targetControl">
''' The AutomationElement of interest.
''' </param>
''' <returns>
''' A TableItemPattern object.
''' </returns>
'''--------------------------------------------------------------------
Private Function GetTableItemPattern( _
ByVal targetControl As AutomationElement) As TableItemPattern
Dim tableItemPattern As TableItemPattern = Nothing
Try
tableItemPattern = DirectCast( _
targetControl.GetCurrentPattern(tableItemPattern.Pattern), TableItemPattern)
Catch exc As InvalidOperationException
' Object doesn't support the
' GridPattern control pattern
Return Nothing
End Try
Return tableItemPattern
End Function 'GetTableItemPattern
...
'''--------------------------------------------------------------------
''' <summary>
''' Obtains a TablePattern control pattern from an
''' AutomationElement.
''' </summary>
''' <param name="targetControl">
''' The AutomationElement of interest.
''' </param>
''' <returns>
''' A TablePattern object.
''' </returns>
'''--------------------------------------------------------------------
Private Function GetTablePattern( _
ByVal targetControl As AutomationElement) As TablePattern
Dim tablePattern As TablePattern = Nothing
Try
tablePattern = DirectCast( _
targetControl.GetCurrentPattern(tablePattern.Pattern), _
TablePattern)
Catch exc As InvalidOperationException
' Object doesn't support the
' TablePattern control pattern
Return Nothing
End Try
Return tablePattern
End Function 'GetTablePattern
...
'''--------------------------------------------------------------------
''' <summary>
''' Set up table item event listeners.
''' </summary>
''' <remarks>
''' The event listener is essentially a focus change listener.
''' Since this is a global desktop listener, a filter would be required
''' to ignore focus change events outside the table.
''' </remarks>
'''--------------------------------------------------------------------
Private Sub SetTableItemEventListeners( _
ByVal targetControl As AutomationElement)
Dim tableItemFocusChangedListener As AutomationFocusChangedEventHandler = _
AddressOf OnTableItemFocusChange
Automation.AddAutomationFocusChangedEventHandler( _
tableItemFocusChangedListener)
End Sub 'SetTableItemEventListeners
...
'''--------------------------------------------------------------------
''' <summary>
''' Event handler for table item focus change.
''' Can be used to track traversal of individual table items
''' within a table.
''' </summary>
''' <param name="src">Object that raised the event.</param>
''' <param name="e">Event arguments.</param>
'''--------------------------------------------------------------------
Private Sub OnTableItemFocusChange( _
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
' Get a TableItemPattern from the source of the event.
Dim tableItemPattern As TableItemPattern = _
GetTableItemPattern(sourceElement)
If tableItemPattern Is Nothing Then
Return
End If
' Get a TablePattern from the container of the current element.
Dim tablePattern As TablePattern = _
GetTablePattern(tableItemPattern.Current.ContainingGrid)
If tablePattern Is Nothing Then
Return
End If
Dim tableItem As AutomationElement = Nothing
Try
tableItem = tablePattern.GetItem( _
tableItemPattern.Current.Row, tableItemPattern.Current.Column)
Catch exc As 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
' is 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 can just record item properties.
Dim controlType As String = _
tableItem.Current.ControlType.LocalizedControlType
Dim columnHeaders As AutomationElement() = _
tableItemPattern.Current.GetColumnHeaderItems()
Dim rowHeaders As AutomationElement() = _
tableItemPattern.Current.GetRowHeaderItems()
Dim itemRow As Integer = tableItemPattern.Current.Row
Dim itemColumn As Integer = tableItemPattern.Current.Column
Dim itemRowSpan As Integer = tableItemPattern.Current.RowSpan
Dim itemColumnSpan As Integer = tableItemPattern.Current.ColumnSpan
End Sub 'OnTableItemFocusChange
'''--------------------------------------------------------------------
''' <summary>
''' Handles the 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 'OnExit
/// -------------------------------------------------------------------
/// <summary>
/// Starts the target application and returns the AutomationElement
/// obtained from the targets window handle.
/// </summary>
/// <param name="exe">
/// The target application.
/// </param>
/// <param name="filename">
/// The text file to be opened in the target application
/// </param>
/// <returns>
/// An AutomationElement representing the target application.
/// </returns>
/// -------------------------------------------------------------------
private AutomationElement StartTarget(string exe, string filename)
{
// Start text editor and load with a text file.
Process p = Process.Start(exe, filename);
// targetApp --> the root AutomationElement
AutomationElement targetApp =
AutomationElement.FromHandle(p.MainWindowHandle);
return targetApp;
}
...
/// -------------------------------------------------------------------
/// <summary>
/// Obtain the table control of interest from the target application.
/// </summary>
/// <param name="targetApp">
/// The target application.
/// </param>
/// <returns>
/// An AutomationElement representing a table control.
/// </returns>
/// -------------------------------------------------------------------
private AutomationElement GetTableElement(AutomationElement targetApp)
{
// The control type we're looking for; in this case 'Document'
PropertyCondition cond1 =
new PropertyCondition(
AutomationElement.ControlTypeProperty,
ControlType.Table);
// The control pattern of interest; in this case 'TextPattern'.
PropertyCondition cond2 =
new PropertyCondition(
AutomationElement.IsTablePatternAvailableProperty,
true);
AndCondition tableCondition = new AndCondition(cond1, cond2);
AutomationElement targetTableElement =
targetApp.FindFirst(TreeScope.Descendants, tableCondition);
// If targetTableElement is null then a suitable table control
// was not found.
return targetTableElement;
}
...
///--------------------------------------------------------------------
/// <summary>
/// Obtains a TableItemPattern control pattern from an
/// AutomationElement.
/// </summary>
/// <param name="targetControl">
/// The AutomationElement of interest.
/// </param>
/// <returns>
/// A TableItemPattern object.
/// </returns>
///--------------------------------------------------------------------
private TableItemPattern GetTableItemPattern(
AutomationElement targetControl)
{
TableItemPattern tableItemPattern = null;
try
{
tableItemPattern =
targetControl.GetCurrentPattern(
TableItemPattern.Pattern)
as TableItemPattern;
}
// Object doesn't support the
// TableItemPattern control pattern
catch (InvalidOperationException)
{
return null;
}
return tableItemPattern;
}
...
///--------------------------------------------------------------------
/// <summary>
/// Obtains a TablePattern control pattern from an
/// AutomationElement.
/// </summary>
/// <param name="targetControl">
/// The AutomationElement of interest.
/// </param>
/// <returns>
/// A TablePattern object.
/// </returns>
///--------------------------------------------------------------------
private TablePattern GetTablePattern(
AutomationElement targetControl)
{
TablePattern tablePattern = null;
try
{
tablePattern =
targetControl.GetCurrentPattern(
TablePattern.Pattern)
as TablePattern;
}
// Object doesn't support the
// TablePattern control pattern
catch (InvalidOperationException)
{
return null;
}
return tablePattern;
}
...
///--------------------------------------------------------------------
/// <summary>
/// Set up table item event listeners.
/// </summary>
/// <remarks>
/// The event listener is essentially a focus change listener.
/// Since this is a global desktop listener, a filter would be required
/// to ignore focus change events outside the table.
/// </remarks>
///--------------------------------------------------------------------
private void SetTableItemEventListeners()
{
AutomationFocusChangedEventHandler tableItemFocusChangedListener =
new AutomationFocusChangedEventHandler(OnTableItemFocusChange);
Automation.AddAutomationFocusChangedEventHandler(
tableItemFocusChangedListener);
}
...
///--------------------------------------------------------------------
/// <summary>
/// Event handler for table item focus change.
/// Can be used to track traversal of individual table items
/// within a table.
/// </summary>
/// <param name="src">Object that raised the event.</param>
/// <param name="e">Event arguments.</param>
///--------------------------------------------------------------------
private void OnTableItemFocusChange(
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;
}
// Get a TableItemPattern from the source of the event.
TableItemPattern tableItemPattern =
GetTableItemPattern(sourceElement);
if (tableItemPattern == null)
{
return;
}
// Get a TablePattern from the container of the current element.
TablePattern tablePattern =
GetTablePattern(tableItemPattern.Current.ContainingGrid);
if (tablePattern == null)
{
return;
}
AutomationElement tableItem = null;
try
{
tableItem = tablePattern.GetItem(
tableItemPattern.Current.Row,
tableItemPattern.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
// is less than zero.
// TO DO: error handling.
}
// Further event processing can be done at this point.
// For the purposes of this sample we can just record item properties.
string controlType =
tableItem.Current.ControlType.LocalizedControlType;
AutomationElement[] columnHeaders =
tableItemPattern.Current.GetColumnHeaderItems();
AutomationElement[] rowHeaders =
tableItemPattern.Current.GetRowHeaderItems();
int itemRow = tableItemPattern.Current.Row;
int itemColumn = tableItemPattern.Current.Column;
int itemRowSpan = tableItemPattern.Current.RowSpan;
int itemColumnSpan = tableItemPattern.Current.ColumnSpan;
}
///--------------------------------------------------------------------
/// <summary>
/// Handles the application shutdown.
/// </summary>
/// <param name="args">Event arguments.</param>
///--------------------------------------------------------------------
protected override void OnExit(System.Windows.ExitEventArgs args)
{
Automation.RemoveAllEventHandlers();
base.OnExit(args);
}
Vea también
Conceptos
Información general acerca de los patrones de control de automatización de la interfaz de usuario
Patrones de controles de UI Automation para clientes
Implementar el patrón de control Table de UI Automation
Implementar el patrón de control TableItem de UI Automation