RangeValuePattern.RangeValuePatternInformation.SmallChange Property
Definition
Important
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Gets the small-change value, unique to the UI Automation element, which is added to or subtracted from the elements Value property.
public:
property double SmallChange { double get(); };
public double SmallChange { get; }
member this.SmallChange : double
Public ReadOnly Property SmallChange As Double
Property Value
The small-change value unique to the UI Automation element or null
if the element does not support SmallChange. The default value is 0.0.
Examples
In the following example, an AutomationElement that supports the RangeValuePattern control pattern has its value incremented or decremented by the control-specific SmallChange value.
SetRangeValue(targetControl[0], rangeValuePattern.Current.SmallChange, 1);
SetRangeValue(targetControl(0), rangeValuePattern.Current.SmallChange, 1)
///--------------------------------------------------------------------
/// <summary>
/// Sets the range value of the control of interest.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <param name="rangeValue">
/// The value (either relative or absolute) to set the control to.
/// </param>
/// <param name="rangeDirection">
/// The value used to specify the direction of adjustment.
/// </param>
///--------------------------------------------------------------------
private void SetRangeValue(
AutomationElement targetControl,
double rangeValue,
double rangeDirection)
{
if (targetControl == null || rangeValue == 0 || rangeDirection == 0)
{
throw new ArgumentException("Argument cannot be null or zero.");
}
RangeValuePattern rangeValuePattern =
GetRangeValuePattern(targetControl);
if (rangeValuePattern.Current.IsReadOnly)
{
throw new InvalidOperationException("Control is read-only.");
}
rangeValue = rangeValue * Math.Sign(rangeDirection);
try
{
if ((rangeValue <= rangeValuePattern.Current.Maximum) ||
(rangeValue >= rangeValuePattern.Current.Minimum))
{
rangeValuePattern.SetValue(rangeValue);
}
}
catch (ArgumentOutOfRangeException)
{
// TO DO: Error handling.
}
catch (ArgumentException)
{
// TO DO: Error handling.
}
}
'''--------------------------------------------------------------------
''' <summary>
''' Sets the range value of the control of interest.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
''' <param name="rangeValue">
''' The value (either relative or absolute) to set the control to.
''' </param>
''' <param name="rangeDirection">
''' The value used to specify the direction of adjustment.
''' </param>
'''--------------------------------------------------------------------
Private Overloads Sub SetRangeValue( _
ByVal targetControl As AutomationElement, _
ByVal rangeValue As Double, ByVal rangeDirection As Double)
If targetControl Is Nothing OrElse _
rangeValue = 0 OrElse rangeDirection = 0 Then
Throw New ArgumentException("Argument cannot be null or zero.")
End If
Dim rangeValuePattern As RangeValuePattern = _
GetRangeValuePattern(targetControl)
If rangeValuePattern.Current.IsReadOnly Then
Throw New InvalidOperationException("Control is read-only.")
End If
rangeValue = rangeValue * Math.Sign(rangeDirection)
Try
If rangeValue <= rangeValuePattern.Current.Maximum OrElse _
rangeValue >= rangeValuePattern.Current.Minimum Then
rangeValuePattern.SetValue(rangeValue)
End If
Catch exc As ArgumentOutOfRangeException
' TO DO: Error handling.
Catch exc As ArgumentException
' TO DO: Error handling.
End Try
End Sub
///--------------------------------------------------------------------
/// <summary>
/// Obtains a RangeValuePattern control pattern from an
/// automation element.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <returns>
/// A RangeValuePattern object.
/// </returns>
///--------------------------------------------------------------------
private RangeValuePattern GetRangeValuePattern(
AutomationElement targetControl)
{
RangeValuePattern rangeValuePattern = null;
try
{
rangeValuePattern =
targetControl.GetCurrentPattern(
RangeValuePattern.Pattern)
as RangeValuePattern;
}
// Object doesn't support the
// RangeValuePattern control pattern
catch (InvalidOperationException)
{
return null;
}
return rangeValuePattern;
}
'''--------------------------------------------------------------------
''' <summary>
''' Obtains a RangeValuePattern control pattern from an
''' automation element.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
''' <returns>
''' A RangeValuePattern object.
''' </returns>
'''--------------------------------------------------------------------
Private Function GetRangeValuePattern( _
ByVal targetControl As AutomationElement) As RangeValuePattern
Dim rangeValuePattern As RangeValuePattern = Nothing
Try
rangeValuePattern = DirectCast( _
targetControl.GetCurrentPattern(rangeValuePattern.Pattern), _
RangeValuePattern)
Catch exc As InvalidOperationException
' Object doesn't support the
' RangeValuePattern control pattern
Return Nothing
End Try
Return rangeValuePattern
End Function 'GetRangeValuePattern