Change Selection in a RichTextBox Programmatically
This example shows how to programmatically change the current selection in a RichTextBox. This selection is the same as if the user had selected the content by using the user interface.
Example
The following Extensible Application Markup Language (XAML) code describes a named RichTextBox control with simple content.
<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
x:Class="SDKSample.ChangeSelectionProgrammaticaly" >
<StackPanel>
<RichTextBox GotMouseCapture="ChangeSelection" Name="richTB">
<FlowDocument>
<Paragraph Name="myParagraph">
<Run>
When the user clicks in the RichTextBox, the selected
text changes programmatically.
</Run>
</Paragraph>
</FlowDocument>
</RichTextBox>
</StackPanel>
</Page>
The following code programmatically selects some arbitrary text when the user clicks inside the RichTextBox.
Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Documents
Namespace SDKSample
Partial Public Class ChangeSelectionProgrammaticaly
Inherits Page
' Change the current selection.
Private Sub ChangeSelection(ByVal sender As Object, ByVal args As RoutedEventArgs)
' Create two arbitrary TextPointers to specify the range of content to select.
Dim myTextPointer1 As TextPointer = myParagraph.ContentStart.GetPositionAtOffset(20)
Dim myTextPointer2 As TextPointer = myParagraph.ContentEnd.GetPositionAtOffset(-10)
' Programmatically change the selection in the RichTextBox.
richTB.Selection.Select(myTextPointer1, myTextPointer2)
End Sub
End Class
End Namespace
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
namespace SDKSample
{
public partial class ChangeSelectionProgrammaticaly : Page
{
// Change the current selection.
void ChangeSelection(Object sender, RoutedEventArgs args)
{
// Create two arbitrary TextPointers to specify the range of content to select.
TextPointer myTextPointer1 = myParagraph.ContentStart.GetPositionAtOffset(20);
TextPointer myTextPointer2 = myParagraph.ContentEnd.GetPositionAtOffset(-10);
// Programmatically change the selection in the RichTextBox.
richTB.Selection.Select(myTextPointer1, myTextPointer2);
}
}
}