語言

ScrollPattern.Scroll(ScrollAmount, ScrollAmount) 方法

定義

可橫向和垂直捲動內容區的可見區域。

public:
 void Scroll(System::Windows::Automation::ScrollAmount horizontalAmount, System::Windows::Automation::ScrollAmount verticalAmount);
public void Scroll(System.Windows.Automation.ScrollAmount horizontalAmount, System.Windows.Automation.ScrollAmount verticalAmount);
member this.Scroll : System.Windows.Automation.ScrollAmount * System.Windows.Automation.ScrollAmount -> unit
Public Sub Scroll (horizontalAmount As ScrollAmount, verticalAmount As ScrollAmount)

參數

horizontalAmount
ScrollAmount

這是針對控制項的水平增量。 NoScroll 如果無法將控制項往此方向滾動,應該會傳入。

verticalAmount
ScrollAmount

垂直增量則是針對控制項的專屬。 NoScroll 如果無法將控制項往此方向滾動,應該會傳入。

例外狀況

控制項只支援 SmallIncrement 水平或垂直捲動的數值,但會傳遞一個 LargeIncrement 數值。

嘗試向無支撐方向捲動。

範例

在以下範例中, ScrollPattern 從 取得 AutomationElement 一個控制模式,然後用來將該元素水平或垂直滾動所需的數量。

///--------------------------------------------------------------------
/// <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 scroll the requested amounts.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <param name="hScrollAmount">
/// The requested horizontal scroll amount.
/// </param>
/// <param name="vScrollAmount">
/// The requested vertical scroll amount.
/// </param>
///--------------------------------------------------------------------
private void ScrollElement(
    AutomationElement targetControl,
    ScrollAmount hScrollAmount,
    ScrollAmount vScrollAmount)
{
    if (targetControl == null)
    {
        throw new ArgumentNullException(
            "AutomationElement argument cannot be null.");
    }

    ScrollPattern scrollPattern = GetScrollPattern(targetControl);

    if (scrollPattern == null)
    {
        return;
    }

    try
    {
        scrollPattern.Scroll(hScrollAmount, vScrollAmount);
    }
    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 scroll the requested amounts.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
''' <param name="hScrollAmount">
''' The requested horizontal scroll amount.
''' </param>
''' <param name="vScrollAmount">
''' The requested vertical scroll amount.
''' </param>
'''--------------------------------------------------------------------
Private Sub ScrollElement( _
ByVal targetControl As AutomationElement, _
ByVal hScrollAmount As ScrollAmount, _
ByVal vScrollAmount 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

    Try
        scrollPattern.Scroll(hScrollAmount, vScrollAmount)
    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

適用於

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