ScrollPattern.ScrollPatternInformation.HorizontallyScrollable Eigenschaft

Definition

Namespace:

System.Windows.Automation

Assembly:

UIAutomationClient.dll

Ruft einen Wert ab, der angibt, ob das Benutzeroberflächenautomatisierungs-Element horizontal gescrollt werden kann.

public:
 property bool HorizontallyScrollable { bool get(); };

public bool HorizontallyScrollable { get; }

member this.HorizontallyScrollable : bool

Public ReadOnly Property HorizontallyScrollable As Boolean

Eigenschaftswert

Boolean

true, wenn das Benutzeroberflächenautomatisierungs-Element horizontal gescrollt werden kann, andernfalls false. Der Standardwert ist false.

Beispiele

Im folgenden Beispiel wird ein ScrollPattern Steuerelementmuster aus einem Benutzeroberflächenautomatisierung-Element abgerufen und anschließend verwendet, um das Element horizontal zu scrollen, der angeforderte Betrag.

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

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

    return scrollPattern;
}

'''--------------------------------------------------------------------
''' <summary>
''' Obtains a ScrollPattern control pattern from an 
''' automation element.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
''' <returns>
''' A ScrollPattern object.
''' </returns>
'''--------------------------------------------------------------------
Private Function GetScrollPattern( _
ByVal targetControl As AutomationElement) As ScrollPattern
    Dim scrollPattern As ScrollPattern = Nothing

    Try
        scrollPattern = DirectCast( _
        targetControl.GetCurrentPattern(scrollPattern.Pattern), _
        ScrollPattern)
    Catch
        ' Object doesn't support the ScrollPattern control pattern
        Return Nothing
    End Try

    Return scrollPattern

End Function 'GetScrollPattern

///--------------------------------------------------------------------
/// <summary>
/// Obtains a ScrollPattern control pattern from an automation 
/// element and attempts to horizontally scroll the requested amount.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <param name="hScrollAmount">
/// The requested horizontal scroll amount.
/// </param>
///--------------------------------------------------------------------
private void ScrollElementHorizontally(
    AutomationElement targetControl,
    ScrollAmount hScrollAmount)
{
    if (targetControl == null)
    {
        throw new ArgumentNullException(
            "AutomationElement argument cannot be null.");
    }

    ScrollPattern scrollPattern = GetScrollPattern(targetControl);

    if (scrollPattern == null)
    {
        return;
    }

    if (!scrollPattern.Current.HorizontallyScrollable)
    {
        return;
    }

    try
    {
        scrollPattern.ScrollHorizontal(hScrollAmount);
    }
    catch (InvalidOperationException)
    {
        // Control not able to scroll in the direction requested;
        // when scrollable property of that direction is False
        // TO DO: error handling.
    }
    catch (ArgumentException)
    {
        // If a control supports SmallIncrement values exclusively 
        // for horizontal or vertical scrolling but a LargeIncrement 
        // value (NaN if not supported) is passed in.
        // TO DO: error handling.
    }
}

'''--------------------------------------------------------------------
''' <summary>
''' Obtains a ScrollPattern control pattern from an automation 
''' element and attempts to horizontally scroll the requested amount.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
''' <param name="hScrollAmount">
''' The requested horizontal scroll amount.
''' </param>
'''--------------------------------------------------------------------
Private Sub ScrollElementHorizontally( _
ByVal targetControl As AutomationElement, _
ByVal hScrollAmount As ScrollAmount)
    If targetControl Is Nothing Then
        Throw New ArgumentNullException( _
        "AutomationElement argument cannot be null.")
    End If

    Dim scrollPattern As ScrollPattern = GetScrollPattern(targetControl)

    If scrollPattern Is Nothing Then
        Return
    End If

    If Not scrollPattern.Current.HorizontallyScrollable Then
        Return
    End If

    Try
        scrollPattern.ScrollHorizontal(hScrollAmount)
    Catch exc As InvalidOperationException
        ' Control not able to scroll in the direction requested;
        ' when scrollable property of that direction is False
        ' TO DO: error handling.
    Catch exc As ArgumentException
        ' If a control supports SmallIncrement values exclusively 
        ' for horizontal or vertical scrolling but a LargeIncrement 
        ' value (NaN if not supported) is passed in.
        ' TO DO: error handling.
    End Try

End Sub

Hinweise

Diese Eigenschaft kann dynamisch sein. Beispielsweise ist der Inhaltsbereich des Benutzeroberflächenautomatisierung-Elements möglicherweise nicht größer als der aktuelle ansichtsfähige Bereich, was bedeutet HorizontallyScrollable false. Die Größe des Benutzeroberflächenautomatisierung-Elements oder das Hinzufügen untergeordneter Elemente kann jedoch die Grenzen des Inhaltsbereichs über den sichtbaren Bereich hinaus erhöhen, der angibt, dass HorizontallyScrollable es sich um einen Wert handelttrue.