html5 clip canvas中使用clip()函数裁剪方法

未使用裁剪绘制一个圆

*{margin:0;padding:0;}

html,body{width:100%;height:100%;overflow:hidden;background-color:#AFAFAF;}

varcanvas=document.getElementById('canvas'),

context=canvas.getContext('2d');

canvas.width=document.body.clientWidth;

canvas.height=document.body.clientHeight;

context.lineWidth=3;

context.strokeStyle='red';

context.beginPath();

context.arc(200,200,100,(Math.PI/180)*0,(Math.PI/180)*360,false);

context.stroke();

context.closePath();