TextSource Class

TextSource Class


Provides an abstract class for specifying character data and formatting properties to be used by the TextFormatter object.

Namespace:   System.Windows.Media.TextFormatting
Assembly:  PresentationCore (in PresentationCore.dll)


public abstract class TextSource


Initializes a new instance of the TextSource class.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Retrieves the text span immediately before the specified TextSource position.


Retrieves a value that maps a TextSource character index to a TextEffect character index.


Retrieves a TextRun starting at a specified TextSource position.


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)

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:


For a complete code sample that shows how to implement a derived TextSource class, see Advanced Text Formatting Sample .

.NET Framework
Available since 3.0

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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