Visual Basic (Declaration)

Public MustInherit Class TextSource

Visual Basic (Usage)

Dim instance As TextSource

C#

public abstract class TextSource

Visual C++

public ref class TextSource abstract

JScript

public abstract class TextSource

XAML

This class is abstract; see Inheritance Hierarchy for derived non-abstract classes usable in XAML.

All access to the text in the TextSource object is through the GetTextRun, which is designed to allow the text layout client to virtualize text in any way it chooses.

TextFormatter is the WPF text engine that provides services for formatting text and breaking text lines. TextFormatter can handle different text character formats and paragraph styles, and includes support for international text layout. Unlike a traditional text API, the TextFormatter interacts with a text layout client through a set of callback methods. It requires the client to provide these methods in an implementation of the TextSource class. The following list describes the three members you must override:

• GetTextRun: Retrieves a TextRun starting at a specified TextSource position.

• GetPrecedingText: Retrieves the text span immediately before the specified TextSource position.

• GetTextEffectCharacterIndexFromTextSourceCharacterIndex: Retrieves a value that maps a TextSource character index to a TextEffect character index.

System..::.Object
  System.Windows.Media.TextFormatting..::.TextSource

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

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0

Reference

Other Resources