此示例演示如何以编程方式更改 RichTextBox 中的当前选定内容。 此选定内容与用户通过用户界面选择的内容相同。
示例
下面的Extensible Application Markup Language (XAML) 代码介绍一个包含简单内容的、已命名的 RichTextBox 控件。
<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>
当用户在 RichTextBox 内部单击时，以下代码以编程方式任意选择一些文本。
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);
}
}
}