getContext method

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Returns an object that provides methods and properties for drawing and manipulating images and graphics on a canvas element in a document. A context object includes information about colors, line widths, fonts, and other graphic parameters that can be drawn on a canvas.

 

Syntax

CanvasRenderingContext2D retVal = object.getContext(contextId, contextAttribute);

Parameters

  • contextId [in]
    Type: string

    The identifier (ID) of the type of canvas to create.

    Internet Explorer 9 and Internet Explorer 10 support only a 2-D context using canvas.getContext("2d");

    IE11 also supports 3-D or WebGL context using canvas.getContext("experimental-webgl");

  • contextAttribute [in, optional]
    IE11 supports an optional set of WebGLContextAttributes for WebGL content. See getContextAttributes for more info.

Standards information

Remarks

The IHTMLCanvasElement::getContext method returns NULL if the contextId value is not supported.

Note  A canvas object only supports one context. Additional calls to IHTMLCanvasElement::getContext this object return the same context.

 

Note  If you are developing on an intranet and have rendering issues for HTML5, you can add a "meta http-equiv-'X-UA-Compatible' content= edge" to the <head> block of a webpage to force Windows Internet Explorer to use the latest standards. You shouldn't use this meta-tag for production webpages. For more information about document compatibility, see Defining Document Compatibility.

 

See also

CanvasRenderingContext2D

WebGL