Provides an abstract class for specifying character data and formatting properties to be used by the TextFormatter object.
Assembly: PresentationCore (in PresentationCore.dll)
All access to the text in the 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 class. The following list describes the three members you must override:
GetPrecedingText: Retrieves the text span immediately before the specified position.
GetTextEffectCharacterIndexFromTextSourceCharacterIndex: Retrieves a value that maps a character index to a TextEffect character index.
For a complete code sample that shows how to implement a derived class, see Advanced Text Formatting Sample.
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.