Статья
11/18/2011

Geometry Class

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Provides a base class for objects that define geometric shapes. Geometry objects can be used for clipping regions and as geometry definitions for rendering two-dimensional graphic data as a Path.

Inheritance Hierarchy

System.Object
  System.Windows.DependencyObject
    System.Windows.Media.Geometry
      System.Windows.Media.EllipseGeometry
      System.Windows.Media.GeometryGroup
      System.Windows.Media.LineGeometry
      System.Windows.Media.PathGeometry
      System.Windows.Media.RectangleGeometry

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

Syntax

'Declaration
Public MustInherit Class Geometry _
    Inherits DependencyObject

public abstract class Geometry : DependencyObject

The Geometry type exposes the following members.

Properties

	Name	Description
	Bounds	Gets a Rect that specifies the axis-aligned bounding box of the Geometry.
	Dispatcher	Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
	Empty	Gets an empty geometry object.
	StandardFlatteningTolerance	Gets the standard tolerance used for polygonal approximation.
	Transform	Gets or sets the Transform object applied to a Geometry.

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Methods

	Name	Description
	CheckAccess	Determines whether the calling thread has access to this object. (Inherited from DependencyObject.)
	ClearValue	Clears the local value of a dependency property. (Inherited from DependencyObject.)
	Equals(Object)	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
	GetAnimationBaseValue	Returns any base value established for a Silverlight dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	GetValue	Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ReadLocalValue	Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
	SetValue	Sets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Fields

	Name	Description
	TransformProperty	Identifies the Transform dependency property.

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Remarks

For XAML syntaxes that take a Geometry, you need to specify a nonabstract derived type of Geometry as an object element. For details, see the XAML syntax on the reference pages for EllipseGeometry, GeometryGroup, LineGeometry, PathGeometry, or RectangleGeometry.

Geometries can be conceptualized as being "simple" or "complex" geometries. EllipseGeometry, LineGeometry, and RectangleGeometry are the simple geometries, which specify the geometrical shape as one element with basic coordinate or dimension properties. GeometryGroup and PathGeometry are the complex geometries. GeometryGroup combines other geometries that it holds as child objects. PathGeometry uses either a set of nested figure/segment path definition elements or a compact string syntax to describe a path for the geometry. For more information, see Geometries or Path Markup Syntax.

A Geometry does not entirely define its own rendering. Instead, a Geometry is provided as data for a Path. Path in turn is a UIElement and therefore participates in the Silverlight 2 rendering system.

Geometry Compared to Shape

The System.Windows.Shapes.Shape class has a Fill, Stroke, and other rendering properties that Geometry and its derived classes lack. The Shape class is a FrameworkElement and therefore participates in the layout system; its derived classes can be used as the content of any element that supports UIElement children.

The Geometry class, on the other hand, simply defines the geometry of a shape, and cannot render itself. Because of its simplicity, it has a wider range of uses.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

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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