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html5 canvas (basic rectangle)_html/css_WEB-ITnose

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Jun 24, 2016 am 11:47 AM

Let’s start with something simple

fillRect(x,y,width,height)

Add a width and height at the coordinates x and y, such as:

fillRect(0,0,500,500)//在坐标0，0处加上一个宽高500的填充矩形

strokeRect(x,y,width,height)

Add a wide and high border rectangle at the coordinates x, y position

but you need to use lineWidth, lineJoin, strokeStyle, miterLimit settings The rectangular function will be given below

clearRect(x,y,width,height)

Clear the position width and height of the coordinates x and y, and the area will be completely transparent

It feels a bit like using a black layer in PS, pulling a rectangular selection box, and then pressing deselect to make it transparent

Then set the fill style

context.fillStyle='#000000'    //填充颜色context.strokeStyle='#ff00ff'    //边框颜色

Full code

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>矩形</title><script src="js/modernizr.js"></script></head><body><script type="text/javascript">window.addEventListener('load',eventWindowLoaded,false);function eventWindowLoaded(){	canvasApp();}function canvasSupport(){	return Modernizr.canvas;}function canvasApp(){	if(!canvasSupport()){		return;	}else{		var theCanvas = document.getElementById('canvas')		var context = theCanvas.getContext("2d")	}	drawScreen();    function drawScreen(){	context.fillStyle="#000000";   //填充黑色	context.strokeStyle='#ff00ff'     //边框为粉色	context.lineWidth=2;              //边框宽度        context.fillRect(10,10,40,40)     //矩形        context.strokeRect(0,0,60,60)    //边框出现的位置        context.clearRect(20,20,20,20)   //清除区域的位置}	}</script><canvas id="canvas" width="500" height="500">你的浏览器无法使用canvas如有疑问加QQ：1035417613;小白童鞋；你的支持是我最大的快乐！！</canvas></body></html>

The result is this

If you don’t understand the previous structure, you can read my previous article http://www.cnblogs.com/LoveOrHate/p/4388321.html

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