TextPattern.RangeFromChild(AutomationElement) 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.

Retrieves a text range enclosing a child element such as an image, hyperlink, Microsoft Excel spreadsheet, or other embedded object.

public:
 System::Windows::Automation::Text::TextPatternRange ^ RangeFromChild(System::Windows::Automation::AutomationElement ^ childElement);

public System.Windows.Automation.Text.TextPatternRange RangeFromChild (System.Windows.Automation.AutomationElement childElement);

member this.RangeFromChild : System.Windows.Automation.AutomationElement -> System.Windows.Automation.Text.TextPatternRange

Public Function RangeFromChild (childElement As AutomationElement) As TextPatternRange

Parameters

childElement: AutomationElement

The enclosed object.

Returns

TextPatternRange

A range that spans the child element.

Exceptions

ArgumentNullException

The child element is null.

InvalidOperationException

The element is not a child of the text container.

Examples

/// -------------------------------------------------------------------
/// <summary>
/// Obtain the text control of interest from the target application.
/// </summary>
/// <param name="targetApp">
/// The target application.
/// </param>
/// <returns>
/// An AutomationElement that represents a text provider..
/// </returns>
/// -------------------------------------------------------------------
private AutomationElement GetTextElement(AutomationElement targetApp)
{
    // The control type we're looking for; in this case 'Document'
    PropertyCondition cond1 =
        new PropertyCondition(
        AutomationElement.ControlTypeProperty,
        ControlType.Document);

    // The control pattern of interest; in this case 'TextPattern'.
    PropertyCondition cond2 = 
        new PropertyCondition(
        AutomationElement.IsTextPatternAvailableProperty, 
        true);

    AndCondition textCondition = new AndCondition(cond1, cond2);

    AutomationElement targetTextElement =
        targetApp.FindFirst(TreeScope.Descendants, textCondition);

    // If targetText is null then a suitable text control was not found.
    return targetTextElement;
}

''' -------------------------------------------------------------------
''' <summary>
''' Obtain the text control of interest from the target application.
''' </summary>
''' <param name="targetApp">
''' The target application.
''' </param>
''' <returns>
''' An AutomationElement. representing a text control.
''' </returns>
''' -------------------------------------------------------------------
Private Function GetTextElement(ByVal targetApp As AutomationElement) As AutomationElement
    ' The control type we're looking for; in this case 'Document'
    Dim cond1 As PropertyCondition = _
        New PropertyCondition( _
        AutomationElement.ControlTypeProperty, _
        ControlType.Document)

    ' The control pattern of interest; in this case 'TextPattern'.
    Dim cond2 As PropertyCondition = _
        New PropertyCondition( _
        AutomationElement.IsTextPatternAvailableProperty, _
        True)

    Dim textCondition As AndCondition = New AndCondition(cond1, cond2)

    Dim targetTextElement As AutomationElement = _
        targetApp.FindFirst(TreeScope.Descendants, textCondition)

    ' If targetText is null then a suitable text control was not found.
    Return targetTextElement
End Function

/// -------------------------------------------------------------------
/// <summary>
/// Obtains a text range spanning an embedded child 
/// of a document control and displays the content of the range.
/// </summary>
/// <param name="targetTextElement">
/// The AutomationElment that represents a text control.
/// </param>
/// -------------------------------------------------------------------
private void GetRangeFromChild(AutomationElement targetTextElement)
{
    TextPattern textPattern =
        targetTextElement.GetCurrentPattern(TextPattern.Pattern)
        as TextPattern;

    if (textPattern == null)
    {
        // Target control doesn't support TextPattern.
        return;
    }

    // Obtain a text range spanning the entire document.
    TextPatternRange textRange = textPattern.DocumentRange;

    // Retrieve the embedded objects within the range.
    AutomationElement[] embeddedObjects = textRange.GetChildren();

    // Retrieve and display text value of embedded object.
    foreach (AutomationElement embeddedObject in embeddedObjects)
    {
        if ((bool)embeddedObject.GetCurrentPropertyValue(
            AutomationElement.IsTextPatternAvailableProperty))
        {
           // For full functionality a secondary TextPattern should
           // be obtained from the embedded object.
           // embeddedObject must be a child of the text provider.
            TextPatternRange embeddedObjectRange =
                textPattern.RangeFromChild(embeddedObject);
            // GetText(-1) retrieves all text in the range.
            // Typically a more limited amount of text would be 
            // retrieved for performance and security reasons.
            Console.WriteLine(embeddedObjectRange.GetText(-1));
        }
    }
}

''' -------------------------------------------------------------------
''' <summary>
''' Obtains a text range spanning an embedded child 
''' of a document control and displays the content of the range.
''' </summary>
''' <param name="targetTextElement">
''' The AutomationElement. representing a text control.
''' </param>
''' -------------------------------------------------------------------
Private Sub GetRangeFromChild( _
ByVal targetTextElement As AutomationElement)
    Dim textPattern As TextPattern = _
    DirectCast( _
    targetTextElement.GetCurrentPattern(textPattern.Pattern), _
    TextPattern)

    If (textPattern Is Nothing) Then
        ' Target control doesn't support TextPattern.
        Return
    End If

    ' Obtain a text range spanning the entire document.
    Dim textRange As TextPatternRange = textPattern.DocumentRange

    ' Retrieve the embedded objects within the range.
    Dim embeddedObjects() As AutomationElement = textRange.GetChildren()

    Dim embeddedObject As AutomationElement
    For Each embeddedObject In embeddedObjects
        If (embeddedObject.GetCurrentPropertyValue( _
            AutomationElement.IsTextPatternAvailableProperty) = True) Then
            ' For full functionality a secondary TextPattern should
            ' be obtained from the embedded object.
            ' embeddedObject must be a child of the text provider.
            Dim embeddedObjectRange As TextPatternRange = _
            textPattern.RangeFromChild(embeddedObject)
            ' GetText(-1) retrieves all text in the range.
            ' Typically a more limited amount of text would be 
            ' retrieved for performance and security reasons.
            Console.WriteLine(embeddedObjectRange.GetText(-1))
        End If
    Next
End Sub

Remarks

If there is no text in the range where the child element exists, a degenerate (empty) range is returned.

The childElement parameter is either a child of the AutomationElement associated with a TextPattern or from the array of children of a TextPatternRange.

Applies to

Deila með