TextPattern.RangeFromChild(AutomationElement) Method

Reference

Definition

Namespace:: System.Windows.Automation

Assembly:: UIAutomationClient.dll

Important

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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

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