Export (0) Print
Expand All

Canvas Class

Defines an area within which you can explicitly position child objects by using coordinates that are relative to the area.

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

'Declaration
Public Class Canvas _
	Inherits Panel
<Canvas ...>
  oneOrMoreUIElements
</Canvas>

XAML Values

oneOrMoreUIElements

One or more object elements that derive from the UIElement class. Object elements defined here become members of the Children collection.

The Canvas type exposes the following members.

  NameDescription
Public methodSupported by Silverlight for Windows PhoneCanvasInitializes a new instance of the Canvas class.
Top

  NameDescription
Public propertySupported by Silverlight for Windows PhoneActualHeightGets the rendered height of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneActualWidthGets the rendered width of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneAllowDropGets 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.)
Public propertySupported by Silverlight for Windows PhoneBackgroundGets or sets a Brush that is used to fill the panel. (Inherited from Panel.)
Public propertySupported by Silverlight for Windows PhoneCacheModeGets or sets a value that indicates that rendered content should be cached when possible. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneChildrenGets the collection of child elements of the panel. (Inherited from Panel.)
Public propertySupported by Silverlight for Windows PhoneClipGets or sets the Geometry used to define the outline of the contents of a UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneCursorGets or sets the cursor image that displays while the mouse pointer is over a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneDataContextGets or sets the data context for a FrameworkElement when it participates in data binding. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneDesiredSizeGets the size that this UIElement computed during the measure pass of the layout process. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneDispatcherGets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
Public propertyEffectGets or sets the pixel shader effect to use for rendering this UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneFlowDirectionGets or sets the direction that text and other user interface elements flow within any parent element that controls their layout. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneHeightGets or sets the suggested height of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneHorizontalAlignmentGets 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.)
Public propertySupported by Silverlight for Windows PhoneIsHitTestVisibleGets or sets whether the contained area of this UIElement can return true values for hit testing. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneIsItemsHostGets a value that indicates whether this Panel is a container for UI items that are generated by an ItemsControl. (Inherited from Panel.)
Public propertySupported by Silverlight for Windows PhoneLanguageGets or sets localization/globalization language information that applies to a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneMarginGets or sets the outer margin of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneMaxHeightGets or sets the maximum height constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneMaxWidthGets or sets the maximum width constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneMinHeightGets or sets the minimum height constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneMinWidthGets or sets the minimum width constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneNameGets 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.)
Public propertySupported by Silverlight for Windows PhoneOpacityGets or sets the degree of the object's opacity. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneOpacityMaskGets or sets the brush used to alter the opacity of regions of this object. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneParentGets the parent object of this FrameworkElement in the object tree. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneProjectionGets or sets the perspective projection (3-D effect) to apply when rendering this UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneRenderSizeGets the final render size of a UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneRenderTransformGets or sets transform information that affects the rendering position of a UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneRenderTransformOriginGets or sets the origin point of any possible render transform declared by RenderTransform, relative to the bounds of the UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows PhoneResourcesGets 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.)
Public propertySupported by Silverlight for Windows PhoneStyleGets or sets an instance Style that is applied for this object during rendering. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneTagGets or sets an arbitrary object value that can be used to store custom information about this object. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneTriggersGets the collection of triggers for animations that are defined for a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows PhoneUseLayoutRoundingGets 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.)
Public propertySupported by Silverlight for Windows PhoneVerticalAlignmentGets 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.)
Public propertySupported by Silverlight for Windows PhoneVisibilityGets 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.)
Public propertySupported by Silverlight for Windows PhoneWidthGets or sets the width of a FrameworkElement. (Inherited from FrameworkElement.)
Top

  NameDescription
Public attached propertySupported by Silverlight for Windows PhoneLeftGets or sets the distance between the left side of an object and the left side of its parent Canvas.
Public attached propertySupported by Silverlight for Windows PhoneTopGets or sets the distance between the top of an element and the top of its parent Canvas.
Public attached propertySupported by Silverlight for Windows PhoneZIndexGets or sets the z-order rendering behavior of objects in a Canvas.
Top

  NameDescription
Public methodSupported by Silverlight for Windows PhoneAddHandlerAdds 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.)
Public methodSupported by Silverlight for Windows PhoneArrangePositions 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.)
Protected methodSupported by Silverlight for Windows PhoneArrangeOverrideProvides the behavior for the "arrange" pass of Silverlight layout. (Overrides FrameworkElement.ArrangeOverride(Size).)
Public methodSupported by Silverlight for Windows PhoneCaptureMouseSets mouse capture to a UIElement. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows PhoneCheckAccessDetermines whether the calling thread has access to this object. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows PhoneClearValueClears the local value of a dependency property. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows PhoneEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by Silverlight for Windows PhoneFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneFindNameRetrieves an object that has the specified identifier name. (Inherited from FrameworkElement.)
Public methodSupported by Silverlight for Windows PhoneGetAnimationBaseValueReturns any base value established for a Silverlight dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows PhoneGetBindingExpressionRetrieves the BindingExpression for a dependency property where a binding is established. (Inherited from FrameworkElement.)
Public methodSupported by Silverlight for Windows PhoneGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodStatic memberSupported by Silverlight for Windows PhoneGetLeftGets the value of the Left attached property for a given object.
Public methodStatic memberSupported by Silverlight for Windows PhoneGetTopGets the value of the Top attached property for a given object.
Public methodSupported by Silverlight for Windows PhoneGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneGetValueReturns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.)
Public methodStatic memberSupported by Silverlight for Windows PhoneGetZIndexGets the value of the ZIndex attached property for a given object.
Public methodSupported by Silverlight for Windows PhoneInvalidateArrangeInvalidates the arrange state (layout) for a UIElement. After the invalidation, the UIElement will have its layout updated, which will occur asynchronously. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows PhoneInvalidateMeasureInvalidates the measurement state (layout) for a UIElement. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows PhoneMeasureUpdates 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.)
Protected methodSupported by Silverlight for Windows PhoneMeasureOverrideProvides the behavior for the "measure" pass of Silverlight layout.  (Overrides FrameworkElement.MeasureOverride(Size).)
Protected methodSupported by Silverlight for Windows PhoneMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneOnApplyTemplateWhen 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.)
Protected methodSupported by Silverlight for Windows PhoneOnCreateAutomationPeerWhen implemented in a derived class, returns class-specific AutomationPeer implementations for the Silverlight automation infrastructure. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows PhoneReadLocalValueReturns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows PhoneReleaseMouseCaptureRemoves mouse capture from a UIElement. After this call, typically no object holds mouse capture. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows PhoneRemoveHandlerRemoves the specified routed event handler from this UIElement. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows PhoneSetBindingAttaches a binding to a FrameworkElement, using the provided binding object, and returns a BindingExpressionBase for possible later use. (Inherited from FrameworkElement.)
Public methodStatic memberSupported by Silverlight for Windows PhoneSetLeftSets the value of the Left attached property for a given object.
Public methodStatic memberSupported by Silverlight for Windows PhoneSetTopSets the value of the Top attached property for a given object.
Public methodSupported by Silverlight for Windows PhoneSetValueSets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject.)
Public methodStatic memberSupported by Silverlight for Windows PhoneSetZIndexSets the value of the ZIndex attached property for a given object.
Public methodSupported by Silverlight for Windows PhoneToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneTransformToVisualReturns a transform object that can be used to transform coordinates from the UIElement to the specified object. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows PhoneUpdateLayoutEnsures that all positions of child objects of a UIElement are properly updated for layout. (Inherited from UIElement.)
Top

  NameDescription
Public eventSupported by Silverlight for Windows PhoneBindingValidationErrorOccurs when a data validation error is reported by a binding source. (Inherited from FrameworkElement.)
Public eventDataContextChangedOccurs when the data context for this element changes. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows PhoneDoubleTapOccurs when a DoubleTap gesture is committed while over this UIElement. (Inherited from UIElement.)
Public eventDragEnterOccurs when the input system reports an underlying drag event with this element as the target. (Inherited from UIElement.)
Public eventDragLeaveOccurs when the input system reports an underlying drag event with this element as the origin. (Inherited from UIElement.)
Public eventDragOverOccurs when the input system reports an underlying drag event with this element as the potential drop target. (Inherited from UIElement.)
Public eventDropOccurs when the input system reports an underlying drop event with this element as the drop target. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneGotFocusOccurs when a UIElement receives focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneHoldOccurs when a Hold gesture is committed while over this UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneKeyDownOccurs when a keyboard key is pressed while the UIElement has focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneKeyUpOccurs when a keyboard key is released while the UIElement has focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneLayoutUpdatedOccurs when the layout of the Silverlight visual tree changes. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows PhoneLoadedOccurs when a FrameworkElement has been constructed and added to the object tree. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows PhoneLostFocusOccurs when a UIElement loses focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneLostMouseCaptureOccurs when the UIElement loses mouse capture. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneManipulationCompletedOccurs when a manipulation and inertia on the UIElement is complete. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneManipulationDeltaOccurs when the input device changes position during a manipulation. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneManipulationStartedOccurs when an input device begins a manipulation on the UIElement. (Inherited from UIElement.)
Public eventMediaCommandOccurs when a button is pressed on a remote control. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneMouseEnterOccurs when the mouse (or a stylus) enters the bounding area of a UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneMouseLeaveOccurs when the mouse (or the stylus) leaves the bounding area of a UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneMouseLeftButtonDownOccurs 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.)
Public eventSupported by Silverlight for Windows PhoneMouseLeftButtonUpOccurs 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.)
Public eventSupported by Silverlight for Windows PhoneMouseMoveOccurs when the coordinate position of the mouse (or stylus) changes while over a UIElement (or while a UIElement holds mouse capture). (Inherited from UIElement.)
Public eventMouseRightButtonDownOccurs when the right mouse button is pressed while the mouse pointer is over a UIElement. (Inherited from UIElement.)
Public eventMouseRightButtonUpOccurs 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.)
Public eventSupported by Silverlight for Windows PhoneMouseWheelOccurs when the user rotates the mouse wheel while the mouse pointer is over a UIElement, or the UIElement has focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneSizeChangedOccurs when either the ActualHeight or the ActualWidth properties change value on a FrameworkElement. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows PhoneTapOccurs when a Tap gesture is committed while over this UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneTextInputOccurs when a UI element gets text in a device-independent manner. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneTextInputStartOccurs when a UI element initially gets text in a device-independent manner. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneTextInputUpdateOccurs when text continues to be composed via an input method editor (IME). (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows PhoneUnloadedOccurs when this object is no longer connected to the main object tree. (Inherited from FrameworkElement.)
Top

  NameDescription
Public fieldStatic memberSupported by Silverlight for Windows PhoneLeftPropertyIdentifies the Left attached property.
Public fieldStatic memberSupported by Silverlight for Windows PhoneTopPropertyIdentifies the Top attached property.
Public fieldStatic memberSupported by Silverlight for Windows PhoneZIndexPropertyIdentifies the ZIndex attached property.
Top

A Canvas is one of the Panel elements that enable layout. Each child object is rendered within the Canvas area. You control the positioning of objects inside the Canvas by specifying x and y coordinates. These coordinates are in pixels. The x and y coordinates are often specified by using the Canvas.Left and Canvas.Top attached properties. Canvas.Left specifies the object's distance from the left side of the containing Canvas (the x-coordinate), and Canvas.Top specifies the object's distance from the top of the containing Canvas (the y-coordinate).

NoteNote:

Because absolute positioning does not take into account the size of the browser window or browser resizing, using Grid or StackPanel as a container is often a better choice. For more information, see Silverlight Layout System.

You can nest Canvas objects. When you nest objects, the coordinates used by each object are relative to its immediate containing Canvas.

Each child object must be a UIElement. In XAML, you declare child objects as object elements that are the inner XML of a Canvas object element. In code, you can manipulate the collection of Canvas child objects by getting the collection that is accessed by the Children property.

You can nest Canvas objects, because a Canvas is a type of UIElement.

In many cases, a Canvas is used solely as a container for other objects and does not have any visible properties. A Canvas is not visible if any of the following conditions are true:

The following example shows how to position a rectangle 30 pixels from the left and 30 pixels from the top of a Canvas.


<Canvas Width="640" Height="480" Background="White">
    <Rectangle Canvas.Left="30" Canvas.Top="30" 
               Fill="red" Width="200" Height="200" />
</Canvas>


The preceding example produces output that is similar to the following illustration.

Positioning a rectangle inside the Canvas

Rectangle positioned 30 down and 30 over.

In the following example, the root (white) Canvas contains a nested (blue) Canvas that has Canvas.Left and Canvas.Top properties of 30. The nested blue Canvas contains a red rectangle that also has Canvas.Left and Canvas.Top values of 30. This creates the effect of a red rectangle bordered by a blue rectangle. This same layout could be achieved using a Border object.


<Canvas Width="300" Height="300" Background="White">
    <Canvas Width="250" Height="250" Canvas.Left="30" 
            Canvas.Top="30" Background="blue">

        <Rectangle Canvas.Left="30" Canvas.Top="30" 
                   Fill="red" Width="200" Height="200" />
    </Canvas>
</Canvas>


The preceding example produces output that is similar to the following illustration.

Nested objects

One rectangle inside another.

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

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

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

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Community Additions

ADD
Show:
© 2014 Microsoft