InkPresenter Class

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Implements a rectangular surface that displays ink strokes.

Inheritance Hierarchy

System.Object
  System.Windows.DependencyObject
    System.Windows.UIElement
      System.Windows.FrameworkElement
        System.Windows.Controls.Panel
          System.Windows.Controls.Canvas
            System.Windows.Controls.InkPresenter

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

Syntax

'Declaration
Public NotInheritable Class InkPresenter _
    Inherits Canvas

public sealed class InkPresenter : Canvas

<InkPresenter>
  oneOrMoreUIElements
</InkPresenter>

XAML Values

• oneOrMoreUIElements
  One or more object elements that derives from UIElement.

The InkPresenter type exposes the following members.

Constructors

	Name	Description
	InkPresenter	Initializes a new instance of the InkPresenter class.

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Properties

	Name	Description
	ActualHeight	Gets the rendered height of a FrameworkElement. (Inherited from FrameworkElement.)
	ActualWidth	Gets the rendered width of a FrameworkElement. (Inherited from FrameworkElement.)
	AllowDrop	Gets or sets a value that determines whether this UIElement can be a drop target for purposes of Silverlight drag-and-drop operations. (Inherited from UIElement.)
	Background	Gets or sets a Brush that is used to fill the panel. (Inherited from Panel.)
	CacheMode	Gets or sets a value that indicates that rendered content should be cached when possible. (Inherited from UIElement.)
	Children	Gets the collection of child elements of the panel. (Inherited from Panel.)
	Clip	Gets or sets the Geometry used to define the outline of the contents of a UIElement. (Inherited from UIElement.)
	Cursor	Gets or sets the cursor image that displays while the mouse pointer is over a FrameworkElement. (Inherited from FrameworkElement.)
	DataContext	Gets or sets the data context for a FrameworkElement when it participates in data binding. (Inherited from FrameworkElement.)
	DesiredSize	Gets the size that this UIElement computed during the measure pass of the layout process. (Inherited from UIElement.)
	Dispatcher	Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
	Effect	Gets or sets the pixel shader effect to use for rendering this UIElement. (Inherited from UIElement.)
	FlowDirection	Gets or sets the direction that text and other user interface elements flow within any parent element that controls their layout. (Inherited from FrameworkElement.)
	Height	Gets or sets the suggested height of a FrameworkElement. (Inherited from FrameworkElement.)
	HorizontalAlignment	Gets or sets the horizontal alignment characteristics that are applied to a FrameworkElement when it is composed in a layout parent, such as a panel or items control. (Inherited from FrameworkElement.)
	IsHitTestVisible	Gets or sets whether the contained area of this UIElement can return true values for hit testing. (Inherited from UIElement.)
	IsItemsHost	Gets a value that indicates whether this Panel is a container for UI items that are generated by an ItemsControl. (Inherited from Panel.)
	Language	Gets or sets localization/globalization language information that applies to a FrameworkElement. (Inherited from FrameworkElement.)
	Margin	Gets or sets the outer margin of a FrameworkElement. (Inherited from FrameworkElement.)
	MaxHeight	Gets or sets the maximum height constraint of a FrameworkElement. (Inherited from FrameworkElement.)
	MaxWidth	Gets or sets the maximum width constraint of a FrameworkElement. (Inherited from FrameworkElement.)
	MinHeight	Gets or sets the minimum height constraint of a FrameworkElement. (Inherited from FrameworkElement.)
	MinWidth	Gets or sets the minimum width constraint of a FrameworkElement. (Inherited from FrameworkElement.)
	Name	Gets or sets the identifying name of the object. When a XAML processor creates the object tree from XAML markup, run-time code can refer to the XAML-declared object by this name. (Inherited from FrameworkElement.)
	Opacity	Gets or sets the degree of the object's opacity. (Inherited from UIElement.)
	OpacityMask	Gets or sets the brush used to alter the opacity of regions of this object. (Inherited from UIElement.)
	Parent	Gets the parent object of this FrameworkElement in the object tree. (Inherited from FrameworkElement.)
	Projection	Gets or sets the perspective projection (3-D effect) to apply when rendering this UIElement. (Inherited from UIElement.)
	RenderSize	Gets the final render size of a UIElement. (Inherited from UIElement.)
	RenderTransform	Gets or sets transform information that affects the rendering position of a UIElement. (Inherited from UIElement.)
	RenderTransformOrigin	Gets or sets the origin point of any possible render transform declared by RenderTransform, relative to the bounds of the UIElement. (Inherited from UIElement.)
	Resources	Gets the locally defined resource dictionary. In XAML, you can establish resource items as child object elements of a frameworkElement.Resources property element, through XAML implicit collection syntax. (Inherited from FrameworkElement.)
	Strokes	Gets or sets the strokes that the InkPresenter displays.
	Style	Gets or sets an instance Style that is applied for this object during rendering. (Inherited from FrameworkElement.)
	Tag	Gets or sets an arbitrary object value that can be used to store custom information about this object. (Inherited from FrameworkElement.)
	Triggers	Gets the collection of triggers for animations that are defined for a FrameworkElement. (Inherited from FrameworkElement.)
	UseLayoutRounding	Gets or sets a value that determines whether rendering for the object and its visual subtree should use rounding behavior that aligns rendering to whole pixels. (Inherited from UIElement.)
	VerticalAlignment	Gets or sets the vertical alignment characteristics that are applied to a FrameworkElement when it is composed in a parent object such as a panel or items control. (Inherited from FrameworkElement.)
	Visibility	Gets or sets the visibility of a UIElement. A UIElement that is not visible does not render and does not communicate its desired size to layout. (Inherited from UIElement.)
	Width	Gets or sets the width of a FrameworkElement. (Inherited from FrameworkElement.)

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Methods

	Name	Description
	AddHandler	Adds a routed event handler for a specified routed event, adding the handler to the handler collection on the current element. Specify handledEventsToo as true to have the provided handler be invoked for routed event that had already been marked as handled by another element along the event route. (Inherited from UIElement.)
	Arrange	Positions child objects and determines a size for a UIElement. Parent objects that implement custom layout for their child elements should call this method from their layout override implementations to form a recursive layout update. (Inherited from UIElement.)
	ArrangeOverride	Provides the behavior for the "arrange" pass of Silverlight layout. (Inherited from Canvas.)
	CaptureMouse	Sets mouse capture to a UIElement. (Inherited from UIElement.)
	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.)
	FindName	Retrieves an object that has the specified identifier name. (Inherited from FrameworkElement.)
	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.)
	GetBindingExpression	Retrieves the BindingExpression for a dependency property where a binding is established. (Inherited from FrameworkElement.)
	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.)
	InvalidateArrange	Invalidates the arrange state (layout) for a UIElement. After the invalidation, the UIElement will have its layout updated, which will occur asynchronously. (Inherited from UIElement.)
	InvalidateMeasure	Invalidates the measurement state (layout) for a UIElement. (Inherited from UIElement.)
	Measure	Updates the DesiredSize of a UIElement. Typically, objects that implement custom layout for their layout children call this method from their own MeasureOverride implementations to form a recursive layout update. (Inherited from UIElement.)
	MeasureOverride	Provides the behavior for the "measure" pass of Silverlight layout.  (Inherited from Canvas.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	OnApplyTemplate	When overridden in a derived class, is invoked whenever application code or internal processes (such as a rebuilding layout pass) call ApplyTemplate. In simplest terms, this means the method is called just before a UI element displays in an application. For more information, see Remarks. (Inherited from FrameworkElement.)
	OnCreateAutomationPeer	When implemented in a derived class, returns class-specific AutomationPeer implementations for the Silverlight automation infrastructure. (Inherited from UIElement.)
	ReadLocalValue	Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
	ReleaseMouseCapture	Removes mouse capture from a UIElement. After this call, typically no object holds mouse capture. (Inherited from UIElement.)
	RemoveHandler	Removes the specified routed event handler from this UIElement. (Inherited from UIElement.)
	SetBinding	Attaches a binding to a FrameworkElement, using the provided binding object, and returns a BindingExpressionBase for possible later use. (Inherited from FrameworkElement.)
	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.)
	TransformToVisual	Returns a transform object that can be used to transform coordinates from the UIElement to the specified object. (Inherited from UIElement.)
	UpdateLayout	Ensures that all positions of child objects of a UIElement are properly updated for layout. (Inherited from UIElement.)

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Events

	Name	Description
	BindingValidationError	Occurs when a data validation error is reported by a binding source. (Inherited from FrameworkElement.)
	DataContextChanged	Occurs when the data context for this element changes. (Inherited from FrameworkElement.)
	DoubleTap	Occurs when a DoubleTap gesture is committed while over this UIElement. (Inherited from UIElement.)
	DragEnter	Occurs when the input system reports an underlying drag event with this element as the target. (Inherited from UIElement.)
	DragLeave	Occurs when the input system reports an underlying drag event with this element as the origin. (Inherited from UIElement.)
	DragOver	Occurs when the input system reports an underlying drag event with this element as the potential drop target. (Inherited from UIElement.)
	Drop	Occurs when the input system reports an underlying drop event with this element as the drop target. (Inherited from UIElement.)
	GotFocus	Occurs when a UIElement receives focus. (Inherited from UIElement.)
	Hold	Occurs when a Hold gesture is committed while over this UIElement. (Inherited from UIElement.)
	KeyDown	Occurs when a keyboard key is pressed while the UIElement has focus. (Inherited from UIElement.)
	KeyUp	Occurs when a keyboard key is released while the UIElement has focus. (Inherited from UIElement.)
	LayoutUpdated	Occurs when the layout of the Silverlight visual tree changes. (Inherited from FrameworkElement.)
	Loaded	Occurs when a FrameworkElement has been constructed and added to the object tree. (Inherited from FrameworkElement.)
	LostFocus	Occurs when a UIElement loses focus. (Inherited from UIElement.)
	LostMouseCapture	Occurs when the UIElement loses mouse capture. (Inherited from UIElement.)
	ManipulationCompleted	Occurs when a manipulation and inertia on the UIElement is complete. (Inherited from UIElement.)
	ManipulationDelta	Occurs when the input device changes position during a manipulation. (Inherited from UIElement.)
	ManipulationStarted	Occurs when an input device begins a manipulation on the UIElement. (Inherited from UIElement.)
	MediaCommand	Occurs when a button is pressed on a remote control. (Inherited from UIElement.)
	MouseEnter	Occurs when the mouse (or a stylus) enters the bounding area of a UIElement. (Inherited from UIElement.)
	MouseLeave	Occurs when the mouse (or the stylus) leaves the bounding area of a UIElement. (Inherited from UIElement.)
	MouseLeftButtonDown	Occurs when the left mouse button is pressed (or when the tip of the stylus touches the tablet) while the mouse pointer is over a UIElement. (Inherited from UIElement.)
	MouseLeftButtonUp	Occurs when the left mouse button is released (or the tip of the stylus is removed from the tablet) while the mouse (or the stylus) is over a UIElement (or while a UIElement holds mouse capture). (Inherited from UIElement.)
	MouseMove	Occurs when the coordinate position of the mouse (or stylus) changes while over a UIElement (or while a UIElement holds mouse capture). (Inherited from UIElement.)
	MouseRightButtonDown	Occurs when the right mouse button is pressed while the mouse pointer is over a UIElement. (Inherited from UIElement.)
	MouseRightButtonUp	Occurs when the right mouse button is released while the mouse pointer is over a UIElement. However, this event will only be raised if a caller marks the preceding MouseRightButtonDown event as handled; see Remarks. (Inherited from UIElement.)
	MouseWheel	Occurs when the user rotates the mouse wheel while the mouse pointer is over a UIElement, or the UIElement has focus. (Inherited from UIElement.)
	SizeChanged	Occurs when either the ActualHeight or the ActualWidth properties change value on a FrameworkElement. (Inherited from FrameworkElement.)
	Tap	Occurs when a Tap gesture is committed while over this UIElement. (Inherited from UIElement.)
	TextInput	Occurs when a UI element gets text in a device-independent manner. (Inherited from UIElement.)
	TextInputStart	Occurs when a UI element initially gets text in a device-independent manner. (Inherited from UIElement.)
	TextInputUpdate	Occurs when text continues to be composed via an input method editor (IME). (Inherited from UIElement.)
	Unloaded	Occurs when this object is no longer connected to the main object tree. (Inherited from FrameworkElement.)

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Fields

	Name	Description
	StrokesProperty	Identifies the Strokes dependency property.

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Remarks

InkPresenter is derived from Canvas and can display one or more UIElement objects and a StrokeCollection.

InkPresenter inherits two properties that relate to presentation: Background and Children.

The Background value for an InkPresenter object is applied behind any strokes that are presented on the surface.

Children values for an InkPresenter render on the InkPresenter surface just as they do on a Canvas. However, the collection of strokes is stored separately in the Strokes property.

Children is the content property for InkPresenter, which is why it is referenced as the oneOrMoreUIElements placeholder in the XAML syntax above. Because the primary purpose of InkPresenter is to display strokes, it is more common to set Children for a Canvas object rather than to specify Children UI elements for an InkPresenter.

All Children items draw over the Background. All Strokes draw over both Children and Background, and you cannot adjust Strokes with Canvas.ZIndex. Therefore, if you want any content to always remain on top of strokes, you should declare that content in a separate Canvas that overlays the InkPresenter, rather than setting the Children property of the InkPresenter in code or as direct element content in XAML.

Note:
If you want to contain the ink within the InkPresenter control, use the Clip property on the InkPresenter.

You can accomplish the following InkPresenter-related tasks with the example code at the specified location.

Task	Example location
Use the InkPresenter element.	InkPresenter
Erase ink in an InkPresenter.	How to: Erase Ink in an InkPresenter
Specify drawing attributes, such as height, width, color, and outline color.	DrawingAttributes
Iterate through the stylus points and manipulate the stroke collection.	StylusPoints
Use the properties of a stylus point, such as X coordinate, Y coordinate, and pressure.	StylusPoint
Retrieve the bounding box for a stroke.	Stroke.GetBounds
Retrieve the bounding box for a stroke collection.	StrokeCollection.GetBounds
Determine whether stroke objects intersect.	Stroke.HitTest
Determine whether stroke collections intersect.	StrokeCollection.HitTest

Examples

The following code example shows basic techniques for capturing input on an InkPresenter surface and using the input to create strokes for display.

Run this sample

<Canvas>
    <TextBlock Text="InkPresenter Control" FontWeight="Bold" Margin="50,30,0,0" />
    <Rectangle Height="500" Width="500" Margin="50,50,0,0" Stroke="Black" />
    <InkPresenter x:Name="MyIP" Height="500" Width="500"
              Margin="50,50,0,0"
              MouseLeftButtonDown="MyIP_MouseLeftButtonDown" 
              LostMouseCapture="MyIP_LostMouseCapture" 
              MouseMove="MyIP_MouseMove" 
              Background="Transparent" Opacity="1" />
</Canvas>

Public Sub New()
    MyBase.New()
    InitializeComponent()
    SetBoundary()
End Sub

'A new stroke object, MyStroke, is created and is added to the StrokeCollection object
'of the InkPresenter, MyIP
Private Sub MyIP_MouseLeftButtonDown(ByVal sender As Object, ByVal e As MouseEventArgs)
    MyIP.CaptureMouse()
    Dim MyStylusPointCollection As StylusPointCollection = New StylusPointCollection
    MyStylusPointCollection.Add(e.StylusDevice.GetStylusPoints(MyIP))
    NewStroke = New Stroke(MyStylusPointCollection)
    MyIP.Strokes.Add(NewStroke)
End Sub

'StylusPoint objects are collected from the MouseEventArgs and added to MyStroke. 
Private Sub MyIP_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
    If (Not (NewStroke) Is Nothing) Then
        NewStroke.StylusPoints.Add(e.StylusDevice.GetStylusPoints(MyIP))
    End If
End Sub

'MyStroke is completed
Private Sub MyIP_LostMouseCapture(ByVal sender As Object, ByVal e As MouseEventArgs)
    NewStroke = Nothing
End Sub

'Set the Clip property of the inkpresenter so that the strokes
'are contained within the boundary of the inkpresenter
Private Sub SetBoundary()
    Dim MyRectangleGeometry As RectangleGeometry = New RectangleGeometry
    MyRectangleGeometry.Rect = New Rect(0, 0, MyIP.ActualWidth, MyIP.ActualHeight)
    MyIP.Clip = MyRectangleGeometry
End Sub

public Page()
{
    InitializeComponent();
    SetBoundary();
}
Stroke NewStroke;

//A new stroke object named MyStroke is created. MyStroke is added to the StrokeCollection of the InkPresenter named MyIP
private void MyIP_MouseLeftButtonDown(object sender, MouseEventArgs e)
{
    MyIP.CaptureMouse();
    StylusPointCollection MyStylusPointCollection = new StylusPointCollection();
    MyStylusPointCollection.Add(e.StylusDevice.GetStylusPoints(MyIP));
    NewStroke = new Stroke(MyStylusPointCollection);
    MyIP.Strokes.Add(NewStroke);
}

//StylusPoint objects are collected from the MouseEventArgs and added to MyStroke. 
private void MyIP_MouseMove(object sender, MouseEventArgs e)
{
    if (NewStroke != null)
        NewStroke.StylusPoints.Add(e.StylusDevice.GetStylusPoints(MyIP));
}

//MyStroke is completed
private void MyIP_LostMouseCapture(object sender, MouseEventArgs e)
{
    NewStroke = null;

}

//Set the Clip property of the inkpresenter so that the strokes
//are contained within the boundary of the inkpresenter
private void SetBoundary()
{
    RectangleGeometry MyRectangleGeometry = new RectangleGeometry();
    MyRectangleGeometry.Rect = new Rect(0, 0, MyIP.ActualWidth, MyIP.ActualHeight);
    MyIP.Clip = MyRectangleGeometry;
}

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.

See Also

Reference

System.Windows.Controls Namespace

Stroke

Canvas

Other Resources

InkPresenter (Silverlight)

Ink Overview