TextSource Class

Reference

Definition

Namespace:: System.Windows.Media.TextFormatting

Assembly:: PresentationCore.dll

Important

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

public ref class TextSource abstract

public abstract class TextSource

type TextSource = class

Public MustInherit Class TextSource

Inheritance: Object
TextSource

Remarks

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.

Note

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

Constructors

TextSource()

Initializes a new instance of the TextSource class.

Properties

PixelsPerDip

Gets or sets the PixelsPerDip at which the text should be rendered.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetPrecedingText(Int32)	Retrieves the text span immediately before the specified TextSource position.
GetTextEffectCharacterIndexFromTextSourceCharacterIndex(Int32)	Retrieves a value that maps a TextSource character index to a TextEffect character index.
GetTextRun(Int32)	Retrieves a TextRun starting at a specified TextSource position.
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Applies to