ValuePattern.SetValue(String) Method

Reference

Definition

Namespace:: System.Windows.Automation

Assembly:: UIAutomationClient.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Sets the value of the control.

public:
 void SetValue(System::String ^ value);

public void SetValue (string value);

member this.SetValue : string -> unit

Public Sub SetValue (value As String)

Parameters

value: String

Value to set. The UI Automation provider is responsible for converting the value to the appropriate data type.

Exceptions

InvalidOperationException

The control is read-only.

ElementNotEnabledException

The control is not enabled.

Examples

In the following example, an AutomationElement that supports the ValuePattern control pattern has its ValueProperty set to a user-specified value.

///--------------------------------------------------------------------
/// <summary>
/// Inserts a string into a text control that supports ValuePattern.
/// </summary>
/// <param name="targetControl">A text control.</param>
/// <param name="value">The string to be inserted.</param>
///--------------------------------------------------------------------
private void InsertText(AutomationElement targetControl,
                                    string value)
{
    // Validate arguments / initial setup
    if (value == null)
        throw new ArgumentNullException(
            "String parameter must not be null.");

    if (targetControl == null)
        throw new ArgumentNullException(
            "AutomationElement parameter must not be null");

    // A series of basic checks prior to attempting an insertion.
    //
    // Check #1: Is control enabled?
    // An alternative to testing for static or read-only controls 
    // is to filter using 
    // PropertyCondition(AutomationElement.IsEnabledProperty, true) 
    // and exclude all read-only text controls from the collection.
    if (!targetControl.Current.IsEnabled)
    {
        throw new InvalidOperationException(
            "The control is not enabled.\n\n");
    }

    // Check #2: Are there styles that prohibit us 
    //           from sending text to this control?
    if (!targetControl.Current.IsKeyboardFocusable)
    {
        throw new InvalidOperationException(
            "The control is not focusable.\n\n");
    }

    // Once you have an instance of an AutomationElement,  
    // check if it supports the ValuePattern pattern.
    object valuePattern = null;

    if (!targetControl.TryGetCurrentPattern(
        ValuePattern.Pattern, out valuePattern))
    {
        // Elements that support TextPattern 
        // do not support ValuePattern and TextPattern
        // does not support setting the text of 
        // multi-line edit or document controls.
        // For this reason, text input must be simulated.
    }
    // Control supports the ValuePattern pattern so we can 
    // use the SetValue method to insert content.
    else
    {
        if (((ValuePattern)valuePattern).Current.IsReadOnly)
        {
            throw new InvalidOperationException(
                "The control is read-only.");
        }
        else
        {
            ((ValuePattern)valuePattern).SetValue(value);
        }
    }
}

'''--------------------------------------------------------------------
''' <summary>
''' Inserts a string into a text control that supports ValuePattern.
''' </summary>
''' <param name="targetControl">A text control.</param>
''' <param name="value">The string to be inserted.</param>
'''--------------------------------------------------------------------
Private Sub InsertText(ByVal targetControl As AutomationElement, _
ByVal value As String)
    ' Validate arguments / initial setup
    If value Is Nothing Then
        Throw New ArgumentNullException( _
        "String parameter must not be null.")
    End If

    If targetControl Is Nothing Then
        Throw New ArgumentNullException( _
        "AutomationElement parameter must not be null")
    End If

    ' A series of basic checks prior to attempting an insertion.
    '
    ' Check #1: Is control enabled?
    ' An alternative to testing for static or read-only controls 
    ' is to filter using 
    ' PropertyCondition(AutomationElement.IsEnabledProperty, true) 
    ' and exclude all read-only text controls from the collection.
    If Not targetControl.Current.IsEnabled Then
        Throw New InvalidOperationException( _
        "The control is not enabled." + vbLf + vbLf)
    End If

    ' Check #2: Are there styles that prohibit us 
    '           from sending text to this control?
    If Not targetControl.Current.IsKeyboardFocusable Then
        Throw New InvalidOperationException( _
        "The control is not focusable." + vbLf + vbLf)
    End If

    ' Once you have an instance of an AutomationElement,  
    ' check if it supports the ValuePattern pattern.
    Dim valuePattern As Object = Nothing

    If Not targetControl.TryGetCurrentPattern( _
    valuePattern.Pattern, valuePattern) Then
        ' Elements that support TextPattern 
        ' do not support ValuePattern and TextPattern
        ' does not support setting the text of 
        ' multi-line edit or document controls.
        ' For this reason, text input must be simulated.
        ' Control supports the ValuePattern pattern so we can 
        ' use the SetValue method to insert content.
    Else
        If CType(valuePattern, ValuePattern).Current.IsReadOnly Then
            Throw New InvalidOperationException("The control is read-only.")
        Else
            CType(valuePattern, ValuePattern).SetValue(value)
        End If
    End If

End Sub

Remarks

Single-line edit controls support programmatic access to their contents through ValuePattern. However, multi-line edit controls do not support the ValuePattern; instead they provide access to their content through the TextPattern control pattern.

Applies to

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