WebCanvas

Class (inherits from WebUIControl)

New in 2012r2

WebCanvas controls are very useful for implementing your own graphical controls because you can use the WebGraphics class to draw inside the WebCanvas region.

Events

Closed Opening Shown ContextualMenuSelected Paint Hidden Pressed

Methods

Close Invalidate UpdateBrowser ExecuteJavaScript Refresh GotoURL SetFocus

Properties

ContextualMenu LockBottom Parent ControlID LockHorizontal Style DiffEngineDisabled LockLeft TabIndex Enabled LockRight Tooltip Height LockVertical Top Indicator Name Visible Left Page Width

Notes

Remember: Browsers maintain an uncompressed raster image of the contents of the canvas in memory so it can be displayed to the user. A 1024x1024 pixel canvas requires 4MB of RAM (4 bytes of color data per pixel). A browser may refuse a request to create a canvas that is too large. For instance iOS5 has a memory limit of 10MB for a single web page (it has been increased to 25MB in iOS6). On a Retina display, canvases require 4 times as much memory as a non-retina display.

Unlike the DesktopCanvas, the WebCanvas cannot act as a parent control to other web controls.

See Also

WebGraphics, Graphics classes; UserGuide:Web Canvas topic