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Visual, classe

Provides rendering support in WPF, which includes hit testing, coordinate transformation, and bounding box calculations.

Espace de noms: System.Windows.Media
Assembly : PresentationCore (dans presentationcore.dll)
Espace de noms XML :

public abstract class Visual : DependencyObject
public abstract class Visual extends DependencyObject
public abstract class Visual extends DependencyObject
Cette classe est abstraite ; consultez Hiérarchie d'héritage pour connaître les classes non abstraites dérivées qui peuvent être utilisées dans XAML.

The Visual class is the basic abstraction from which every FrameworkElement object derives. It also serves as the entry point for writing new controls in WPF, and in many ways can be thought of as the window handle (HWND) in the Win32 application model.

The Visual object is a core WPF object, whose primary role is to provide rendering support. User interface controls, such as Button and TextBox, derive from the Visual class, and use it for persisting their rendering data. The Visual object provides support for:

  • Output display: Rendering the persisted, serialized drawing content of a visual.

  • Transformations: Performing transformations on a visual.

  • Clipping: Providing clipping region support for a visual.

  • Hit testing: Determining whether a coordinate or geometry is contained within the bounds of a visual.

  • Bounding box calculations: Determining the bounding rectangle of a visual.

However, the Visual object does not include support for non-rendering features, such as:

  • Event handling

  • Layout

  • Styles

  • Data binding

  • Globalization

Visual is exposed as a public abstract class from which child classes must be derived. The following illustration shows the hierarchy of the visual objects that are exposed in WPF.

Visual class hierarchy

Diagram of classes derived from the Visual object

For more information, see Windows Presentation Foundation Graphics Rendering Overview.

Les membres statiques publics (Shared en Visual Basic) de ce type sont thread-safe. Il n'est pas garanti que les membres d'instance soient thread-safe.

Microsoft .NET Framework 3.0 est pris en charge sur Windows Vista, Microsoft Windows XP SP2 et Windows Server 2003 SP1.

.NET Framework

Prise en charge dans : 3.0

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