Статья
11/18/2011

TextSelection Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Encapsulates the selection state for the RichTextBox control.

Inheritance Hierarchy

System.Object
System.Windows.Documents.TextSelection

Namespace: System.Windows.Documents
Assembly: System.Windows (in System.Windows.dll)

Syntax

'Declaration
Public NotInheritable Class TextSelection

public sealed class TextSelection

The TextSelection type exposes the following members.

Properties

	Name	Description
	End	Gets a TextPointer that represents the end of the current selection.
	Start	Gets a TextPointer that represents the beginning of the current selection.
	Text	Gets or sets the plain text contents of the current selection.
	Xaml	Gets or sets the XAML representation of the current selection.

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Methods

	Name	Description
	ApplyPropertyValue	Applies the specified formatting property and value to the current selection.
	Equals(Object)	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetPropertyValue	Gets the value of the specified formatting property on the current selection.
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	Insert	Inserts or replaces the content at the current selection as a TextElement.
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	Select	Updates the current selection, taking two TextPointer positions to indicate the updated selection.
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Remarks

The TextSelection class represents the selection of text in the RichTextBox. This type has no public constructor, but you can access the currently selected text in the RichTextBox by using the RichTextBox.Selection property. To perform operations on the selected text, you can use the GetPropertyValue and ApplyPropertyValue methods.

Examples

The following example shows how to apply bold, italic, and underline formatting to selected text.

Run this sample

<!--Create a RichTextBox and three buttons.-->
<StackPanel>
    <RichTextBox x:Name="MyRTB" Width="600" Height="400" />
    <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
        <Button Content="Bold" Height="30" Margin="2" Width="50" Click="BtnBold_Click" />
        <Button Content="Italic" Height="30" Margin="2" Width="50" Click="BtnItalic_Click" />
        <Button Content="Underline" Height="30" Margin="2" Width="65" Click="BtnUnderline_Click" />
    </StackPanel>
</StackPanel>

'Set Bold formatting to selected content
Private Sub BtnBold_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    If MyRTB IsNot Nothing Then
        If TypeOf MyRTB.Selection.GetPropertyValue(Run.FontWeightProperty) Is FontWeight _
            AndAlso (CType(MyRTB.Selection.GetPropertyValue(Run.FontWeightProperty), FontWeight) = FontWeights.Normal) Then
            MyRTB.Selection.ApplyPropertyValue(Run.FontWeightProperty, FontWeights.Bold)
        Else
            MyRTB.Selection.ApplyPropertyValue(Run.FontWeightProperty, FontWeights.Normal)
        End If
    End If
End Sub


'Set Italic formatting to selected content
Private Sub BtnItalic_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    If MyRTB IsNot Nothing Then
        If TypeOf MyRTB.Selection.GetPropertyValue(Run.FontStyleProperty) Is FontStyle _
            AndAlso (CType(MyRTB.Selection.GetPropertyValue(Run.FontStyleProperty), FontStyle) = FontStyles.Normal) Then
            MyRTB.Selection.ApplyPropertyValue(Run.FontStyleProperty, FontStyles.Italic)
        Else
            MyRTB.Selection.ApplyPropertyValue(Run.FontStyleProperty, FontStyles.Normal)
        End If
    End If
End Sub


'Set Underline formatting to selected content
Private Sub BtnUnderline_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    If (Not (MyRTB) Is Nothing) Then
        If (MyRTB.Selection.GetPropertyValue(Run.TextDecorationsProperty) Is Nothing) Then
            MyRTB.Selection.ApplyPropertyValue(Run.TextDecorationsProperty, TextDecorations.Underline)
        Else
            MyRTB.Selection.ApplyPropertyValue(Run.TextDecorationsProperty, Nothing)
        End If
    End If
End Sub

//Set Bold formatting to selected content
private void BtnBold_Click(object sender, RoutedEventArgs e)
{
    if (MyRTB != null)
    {
        if (MyRTB.Selection.GetPropertyValue(Run.FontWeightProperty) is FontWeight && ((FontWeight)MyRTB.Selection.GetPropertyValue(Run.FontWeightProperty)) == FontWeights.Normal)
            MyRTB.Selection.ApplyPropertyValue(Run.FontWeightProperty, FontWeights.Bold);
        else
            MyRTB.Selection.ApplyPropertyValue(Run.FontWeightProperty, FontWeights.Normal);

    }

}
//<SnippetItalic>
//Set Italic formatting to selected content
private void BtnItalic_Click(object sender, RoutedEventArgs e)
{
    if (MyRTB != null)
    {
        if (MyRTB.Selection.GetPropertyValue(Run.FontStyleProperty) is FontStyle && ((FontStyle)MyRTB.Selection.GetPropertyValue(Run.FontStyleProperty)) == FontStyles.Normal)
            MyRTB.Selection.ApplyPropertyValue(Run.FontStyleProperty, FontStyles.Italic);
        else
            MyRTB.Selection.ApplyPropertyValue(Run.FontStyleProperty, FontStyles.Normal);
    }


}

//Set Underline formatting to selected content
private void BtnUnderline_Click(object sender, RoutedEventArgs e)
{
    if (MyRTB != null)
    {
        if (MyRTB.Selection.GetPropertyValue(Run.TextDecorationsProperty) == null)
            MyRTB.Selection.ApplyPropertyValue(Run.TextDecorationsProperty, TextDecorations.Underline);
        else
            MyRTB.Selection.ApplyPropertyValue(Run.TextDecorationsProperty, null);
    }

}

Version Information

Silverlight

Supported in: 5, 4

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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