ScrollPattern.SetScrollPercent(Double, Double) 方法

定義

命名空間:

System.Windows.Automation

組件:

UIAutomationClient.dll

設定水平和/或垂直捲動位置，此值以其在 AutomationElement 內總內容區域的百分比來表示。

public:
 void SetScrollPercent(double horizontalPercent, double verticalPercent);

public void SetScrollPercent (double horizontalPercent, double verticalPercent);

member this.SetScrollPercent : double * double -> unit

Public Sub SetScrollPercent (horizontalPercent As Double, verticalPercent As Double)

參數

horizontalPercent

Double

總水平內容區域的百分比。 如果無法以這個方向捲動控制項，則應傳入NoScroll 。

verticalPercent

Double

總垂直內容區域的百分比。 如果無法以這個方向捲動控制項，則應傳入NoScroll 。

例外狀況

ArgumentException

傳入的值無法轉換成雙精度浮點數。

ArgumentOutOfRangeException

傳入的值大於 100 或小於 0 (-1 例外，因為它相當於 NoScroll)。 HorizontalScrollPercent 和 VerticalScrollPercent 的值標準化為 0% 或 100%。

InvalidOperationException

嘗試以不支援的方向捲動。

範例

在下列範例中， ScrollPattern 控制項模式是從 取得 AutomationElement ，然後用來將可檢視區域捲動到內容區域的左上方 'home' 位置。

///--------------------------------------------------------------------
/// <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 to the 'home' position.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
///--------------------------------------------------------------------
private void ScrollHome(AutomationElement targetControl)
{
    if (targetControl == null)
    {
        throw new ArgumentNullException(
            "AutomationElement argument cannot be null.");
    }

    ScrollPattern scrollPattern = GetScrollPattern(targetControl);

    if (scrollPattern == null)
    {
        return;
    }

    try
    {
        scrollPattern.SetScrollPercent(0, 0);
    }
    catch (InvalidOperationException)
    {
        // Control not able to scroll in the direction requested;
        // when scrollable property of that direction is False
        // TO DO: error handling.
    }
    catch (ArgumentOutOfRangeException)
    {
        // A value greater than 100 or less than 0 is passed in 
        // (except -1 which is equivalent to NoScroll).
        // TO DO: error handling.
    }
}

'''--------------------------------------------------------------------
''' <summary>
''' Obtains a ScrollPattern control pattern from an automation 
''' element and attempts to scroll to the top left 'home' position.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
'''--------------------------------------------------------------------
Private Sub ScrollHome(ByVal targetControl As AutomationElement) 
    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.SetScrollPercent(0, 0)
    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 ArgumentOutOfRangeException
        ' A value greater than 100 or less than 0 is passed in 
        ' (except -1 which is equivalent to NoScroll).
        ' TO DO: error handling.
    End Try

End Sub

備註

只有在控制項的內容區域大於可見區域時，這個方法才有用。

傳入值 NoScroll 表示指定的方向沒有捲動。