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StreamGeometry Class

Defines a geometric shape, described using a StreamGeometryContext. This geometry is light-weight alternative to PathGeometry: it does not support data binding, animation, or modification.

Namespace:  System.Windows.Media
Assembly:  PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation

'Declaration
<TypeConverterAttribute(GetType(GeometryConverter))> _
Public NotInheritable Class StreamGeometry _
	Inherits Geometry
<StreamGeometry .../>
<object property="moveAndDrawCommands"/>

XAML Values

moveAndDrawCommands

One or more move and draw commands. See Path Markup Syntax.

The StreamGeometry type exposes the following members.

  NameDescription
Public methodStreamGeometryInitializes a new, empty instance of the StreamGeometry class.
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  NameDescription
Public propertyBoundsGets a Rect that is exactly large enough to contain this StreamGeometry. (Overrides Geometry.Bounds.)
Public propertyCanFreezeGets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.)
Public propertyDependencyObjectTypeGets the DependencyObjectType that wraps the CLR type of this instance.  (Inherited from DependencyObject.)
Public propertyDispatcherGets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)
Public propertyFillRuleGets or sets a value that determines how the intersecting areas contained in this StreamGeometry are combined.
Public propertyHasAnimatedPropertiesGets a value that indicates whether one or more AnimationClock objects is associated with any of this object's dependency properties. (Inherited from Animatable.)
Public propertyIsFrozenGets a value that indicates whether the object is currently modifiable. (Inherited from Freezable.)
Public propertyIsSealedGets a value that indicates whether this instance is currently sealed (read-only). (Inherited from DependencyObject.)
Public propertyTransformGets or sets the Transform object applied to a Geometry. (Inherited from Geometry.)
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  NameDescription
Public methodApplyAnimationClock(DependencyProperty, AnimationClock)Applies an AnimationClock to the specified DependencyProperty. If the property is already animated, the SnapshotAndReplace handoff behavior is used. (Inherited from Animatable.)
Public methodApplyAnimationClock(DependencyProperty, AnimationClock, HandoffBehavior)Applies an AnimationClock to the specified DependencyProperty. If the property is already animated, the specified HandoffBehavior is used. (Inherited from Animatable.)
Public methodBeginAnimation(DependencyProperty, AnimationTimeline)Applies an animation to the specified DependencyProperty. The animation is started when the next frame is rendered. If the specified property is already animated, the SnapshotAndReplace handoff behavior is used. (Inherited from Animatable.)
Public methodBeginAnimation(DependencyProperty, AnimationTimeline, HandoffBehavior)Applies an animation to the specified DependencyProperty. The animation is started when the next frame is rendered. If the specified property is already animated, the specified HandoffBehavior is used. (Inherited from Animatable.)
Public methodCheckAccessDetermines whether the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)
Public methodClearRemoves all geometric information from this StreamGeometry.
Public methodClearValue(DependencyProperty)Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.)
Public methodClearValue(DependencyPropertyKey)Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.)
Public methodCloneCreates a modifiable clone of this StreamGeometry, making deep copies of this object's values. When copying dependency properties, this method copies resource references and data bindings (but they might no longer resolve) but not animations or their current values.
Public methodCloneCurrentValueCreates a modifiable clone of this StreamGeometry object, making deep copies of this object's current values. Resource references, data bindings, and animations are not copied, but their current values are.
Public methodCoerceValueCoerces the value of the specified dependency property. This is accomplished by invoking any CoerceValueCallback function specified in property metadata for the dependency property as it exists on the calling DependencyObject. (Inherited from DependencyObject.)
Public methodEqualsDetermines whether a provided DependencyObject is equivalent to the current DependencyObject. (Inherited from DependencyObject.)
Public methodFillContains(Geometry)Indicates whether the current geometry completely contains the specified Geometry. (Inherited from Geometry.)
Public methodFillContains(Point)Indicates whether the geometry contains the specified Point. (Inherited from Geometry.)
Public methodFillContains(Geometry, Double, ToleranceType)Indicates whether the current geometry contains the specified Geometry, given the specified margin of error. (Inherited from Geometry.)
Public methodFillContains(Point, Double, ToleranceType)Indicates whether the geometry contains the specified Point, given the specified margin of error. (Inherited from Geometry.)
Public methodFillContainsWithDetail(Geometry)Returns a value that describes the intersection between the current geometry and the specified geometry. (Inherited from Geometry.)
Public methodFillContainsWithDetail(Geometry, Double, ToleranceType)Returns a value that describes the intersection between the current geometry and the specified geometry, given the specified margin of error. (Inherited from Geometry.)
Public methodFreezeMakes the current object unmodifiable and sets its IsFrozen property to true. (Inherited from Freezable.)
Public methodGetAnimationBaseValueReturns the non-animated value of the specified DependencyProperty. (Inherited from Animatable.)
Public methodGetAreaGets the area of the filled region of the Geometry object. (Inherited from Geometry.)
Public methodGetArea(Double, ToleranceType)Gets the area, within the specified tolerance, of the filled region of the Geometry object. (Inherited from Geometry.)
Public methodGetAsFrozenCreates a frozen copy of the Freezable, using base (non-animated) property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.)
Public methodGetCurrentValueAsFrozenCreates a frozen copy of the Freezable using current property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.)
Public methodGetFlattenedPathGeometryGets a PathGeometry that is a polygonal approximation of the Geometry object. (Inherited from Geometry.)
Public methodGetFlattenedPathGeometry(Double, ToleranceType)Gets a PathGeometry, within the specified tolerance, that is a polygonal approximation of the Geometry object. (Inherited from Geometry.)
Public methodGetHashCodeGets a hash code for this DependencyObject. (Inherited from DependencyObject.)
Public methodGetLocalValueEnumeratorCreates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.)
Public methodGetOutlinedPathGeometryGets a PathGeometry that is a simplified outline of the filled region of the Geometry. (Inherited from Geometry.)
Public methodGetOutlinedPathGeometry(Double, ToleranceType)Gets a PathGeometry, within the specified tolerance, that is a simplified outline of the filled region of the Geometry. (Inherited from Geometry.)
Public methodGetRenderBounds(Pen)Returns an axis-aligned rectangle that is exactly large enough to contain the geometry after it has been outlined with the specified Pen. (Inherited from Geometry.)
Public methodGetRenderBounds(Pen, Double, ToleranceType)Returns an axis-aligned rectangle that is exactly large enough to contain the geometry after it has been outlined with the specified Pen, given the specified tolerance factor. (Inherited from Geometry.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodGetValueReturns the current effective value of a dependency property on this instance of a DependencyObject. (Inherited from DependencyObject.)
Public methodGetWidenedPathGeometry(Pen)Gets a PathGeometry that is the shape defined by the stroke on the Geometry produced by the specified Pen. (Inherited from Geometry.)
Public methodGetWidenedPathGeometry(Pen, Double, ToleranceType)Gets a PathGeometry that is the shape defined by the stroke on the Geometry produced by the specified Pen, given the specified tolerance factor. (Inherited from Geometry.)
Public methodInvalidatePropertyRe-evaluates the effective value for the specified dependency property (Inherited from DependencyObject.)
Public methodIsEmptyDetermines whether this StreamGeometry describes a geometric shape. (Overrides Geometry.IsEmpty.)
Public methodMayHaveCurvesDetermines whether this StreamGeometry contains a curved segment. (Overrides Geometry.MayHaveCurves.)
Public methodOpenOpens a StreamGeometryContext that can be used to describe this StreamGeometry object's contents.
Public methodReadLocalValueReturns the local value of a dependency property, if it exists. (Inherited from DependencyObject.)
Public methodSetCurrentValueSets the value of a dependency property without changing its value source. (Inherited from DependencyObject.)
Public methodSetValue(DependencyProperty, Object)Sets the local value of a dependency property, specified by its dependency property identifier. (Inherited from DependencyObject.)
Public methodSetValue(DependencyPropertyKey, Object)Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.)
Protected methodShouldSerializePropertyReturns a value that indicates whether serialization processes should serialize the value for the provided dependency property. (Inherited from DependencyObject.)
Public methodShouldSerializeTransformGets a value that indicates whether the value of the Transform property should be serialized. (Inherited from Geometry.)
Public methodStrokeContains(Pen, Point)Determines whether the specified Point is contained in the stroke produced by applying the specified Pen to the geometry. (Inherited from Geometry.)
Public methodStrokeContains(Pen, Point, Double, ToleranceType)Determines whether the specified Point is contained in the stroke produced by applying the specified Pen to the geometry, given the specified margin of error. (Inherited from Geometry.)
Public methodStrokeContainsWithDetail(Pen, Geometry)Returns a value that describes the intersection between the specified Geometry and the stroke created by applying the specified Pen to the current geometry. (Inherited from Geometry.)
Public methodStrokeContainsWithDetail(Pen, Geometry, Double, ToleranceType)Gets a value that describes the intersection between the specified Geometry and the stroke created by applying the specified Pen to the current geometry, given the specified margin of error. (Inherited from Geometry.)
Public methodToStringCreates a string representation of the object based on the current culture. (Inherited from Geometry.)
Public methodToString(IFormatProvider)Creates a string representation of the object using the specified culture-specific formatting information. (Inherited from Geometry.)
Public methodVerifyAccessEnforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)
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  NameDescription
Public eventChangedOccurs when the Freezable or an object it contains is modified. (Inherited from Freezable.)
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  NameDescription
Public fieldStatic memberFillRulePropertyIdentifies the FillRule dependency property.
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  NameDescription
Explicit interface implemetationPrivate methodIFormattable.ToStringFormats the value of the current instance using the specified format. (Inherited from Geometry.)
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Use a StreamGeometry when you need to describe a complex geometry but do not want the overhead of supporting data binding, animation, or modification. Because of its efficiency, the StreamGeometry class is a good choice for describing adorners.

A StreamGeometry cannot be serialized if it contains a Transform or any non-stroked or unfilled segments.

Freezable Features

A StreamGeometry is a Freezable type. For information about Freezable features, such as freezing and cloning, see the Freezable Objects Overview.

StreamGeometry is light-weight alternative to PathGeometry for creating geometric shapes. Use a StreamGeometry when you need to describe a complex geometry but do not want the overhead of supporting data binding, animation, or modification. For example, because of its efficiency, the StreamGeometry class is a good choice for describing adorners.

The following example uses attribute syntax to create a triangular StreamGeometry in XAML.

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <StackPanel>

    <Path Data="F0 M10,100 L100,100 100,50Z" 
      StrokeThickness="1" Stroke="Black"/>

  </StackPanel>
</Page>

For more information about StreamGeometry attribute syntax, see the Path Markup Syntax page.

The next example uses a StreamGeometry to define a triangle in code. First, the example creates a StreamGeometry, then obtains a StreamGeometryContext and uses it to describe the triangle.


Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Shapes

Namespace SDKSample
	' Use StreamGeometry with StreamGeometryContext to define a triangle shape.
	Partial Public Class StreamGeometryTriangleExample
		Inherits Page
		Public Sub New()
			' Create a path to draw a geometry with.
			Dim myPath As New Path()
			myPath.Stroke = Brushes.Black
			myPath.StrokeThickness = 1

			' Create a StreamGeometry to use to specify myPath.
			Dim geometry As New StreamGeometry()
			geometry.FillRule = FillRule.EvenOdd

			' Open a StreamGeometryContext that can be used to describe this StreamGeometry 
			' object's contents.
			Using ctx As StreamGeometryContext = geometry.Open()

				' Begin the triangle at the point specified. Notice that the shape is set to 
				' be closed so only two lines need to be specified below to make the triangle.
				ctx.BeginFigure(New Point(10, 100), True, True) ' is closed  -  is filled 

				' Draw a line to the next specified point.
				ctx.LineTo(New Point(100, 100), True, False) ' is smooth join  -  is stroked 

				' Draw another line to the next specified point.
				ctx.LineTo(New Point(100, 50), True, False) ' is smooth join  -  is stroked 
			End Using

			' Freeze the geometry (make it unmodifiable)
			' for additional performance benefits.
			geometry.Freeze()

			' Specify the shape (triangle) of the Path using the StreamGeometry.
			myPath.Data = geometry

			' Add path shape to the UI.
			Dim mainPanel As New StackPanel()
			mainPanel.Children.Add(myPath)
			Me.Content = mainPanel
		End Sub
	End Class
End Namespace

The next example creates a method that uses a StreamGeometry and StreamGeometryContext to define a geometric shape based on specified parameters.


Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Shapes

Namespace SDKSample
	Partial Public Class StreamGeometryExample
		Inherits Page
		Public Sub New()
			' Create a path to draw a geometry with.
			Dim myPath As New Path()
			myPath.Stroke = Brushes.Black
			myPath.StrokeThickness = 1

			' Create a StreamGeometry to use to specify myPath.
			Dim theGeometry As StreamGeometry = BuildRegularPolygon(New Point(200, 200), 200, 8, 0)
			theGeometry.FillRule = FillRule.EvenOdd

			' Freeze the geometry (make it unmodifiable)
			' for additional performance benefits.
			theGeometry.Freeze()

			' Use the StreamGeometry returned by the BuildRegularPolygon to 
			' specify the shape of the path.
			myPath.Data = theGeometry

			' Add path shape to the UI.
			Dim mainPanel As New StackPanel()
			mainPanel.Children.Add(myPath)
			Me.Content = mainPanel
		End Sub

		Private Function BuildRegularPolygon(ByVal c As Point, ByVal r As Double, ByVal numSides As Integer, ByVal offsetDegree As Double) As StreamGeometry
			' c is the center, r is the radius,
			' numSides the number of sides, offsetDegree the offset in Degrees.
			' Do not add the last point.

			Dim geometry As New StreamGeometry()

			Using ctx As StreamGeometryContext = geometry.Open()
				ctx.BeginFigure(New Point(), True, True) ' is closed  -  is filled 

				Dim [step] As Double = 2 * Math.PI / Math.Max(numSides, 3)
				Dim cur As Point = c

				Dim a As Double = Math.PI * offsetDegree / 180.0
				Dim i As Integer = 0
				Do While i < numSides
					cur.X = c.X + r * Math.Cos(a)
					cur.Y = c.Y + r * Math.Sin(a)
					ctx.LineTo(cur, True, False) ' is smooth join  -  is stroked 
					i += 1
					a += [step]
				Loop
			End Using

			Return geometry
		End Function
	End Class
End Namespace

.NET Framework

Supported in: 4.5.3, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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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