How to use the Canvas tag of HTML5

This article mainly introduces the "HTML5 Canvas tag how to use" related knowledge, editor through the actual case to show you the operation process, the method of operation is simple and fast, practical, I hope that this "HTML5 Canvas tag how to use" article can help you solve the problem.

HTML 5 tag definition and usage

Tags define graphics, such as charts and other images.

Labels are just graphics containers, and you must use scripts to draw graphics.

Example

How to display a red rectangle through the canvas element:

Var canvas=document.getElementById ('myCanvas'); var ctx=canvas.getContext (' 2d'); ctx.fillStyle='#FF0000';ctx.fillRect (0meme 0mem80100)

Defines the state-based drawing of the graph

Most Canvas drawing API is not defined in the

The element itself is defined on a "drawing environment" object obtained through the canvas's getContext () method:

Canvas.width canvas.height / / specifies the width and height canvas.getContext of the canvas ("2d") / / return to the drawing environment context.moveTo (10Power10) / / start drawing context.lineTo (100100) / / start drawing from (10Power10) to (100100) context.stroke () / / start drawing (line) context.lineWidth=3 / / set the width of the line context.strokeStyle= "# f00" set the meaning of the line color stroke strokes context.fillStyle= "rgb (255p0p0)" Context.fill () / / Color, fill the color (color block) context.beginPath (); / / define a new path context.closePath (); / / it is used at the end of the path. If the path drawn is not closed, it will be closed automatically. If you do not write closrPath, it will not be closed / / starting from the coordinates (20,030), draw a rectangle context.fillRect of 64cm 36. / / rect rectangle / / draw arcs and circles context.arc (centetx,centery,radius, / / center coordinates and radius startingAngle,enddingAngle, / / which arc value starts and ends with which arc value anticlockwise=false / / optional, indicating whether to start clockwise or counterclockwise. Default: clockwise. True draws counterclockwise) / / calls the arc function / / draws an arc with (300300) as the center, 200 as the radius, and draws an arc from 0 to 1.5 PIcontext.arc (300, 300, 200, 200, and 1.5 minutes) / / the global variable WINDOW_WIDTH=1024; WINDOW_HEIGHT=768;// calls the global variable canvas.width=WINDOW_WIDTH;//render () function render (context) This is the end of renderDigit's content on "how to use the Canvas tag of HTML5". Thank you for your reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.