javascript+html5实现绘制圆环的方法
内容摘要
本文实例讲述了javascript+html5实现绘制圆环的方法。分享给大家供大家参考。具体如下:
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文章正文
本文实例讲述了javascript+html5实现绘制圆环的方法。分享给大家供大家参考。具体如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 | <!DOCTYPE html> <html> <head> <title> </title> <meta http-equiv= "Content-Type" content= "text/html;charset=UTF-8" > </head> <body> <fieldset> <canvas id= "myCanvas" width= "400px" height= "400px" >Your browser does not support the HTML5 canvas tag.</canvas> </fieldset> <script type= "text/javascript" > function yuanhuan(ctx,data,option){ var cood=option.cood; var radius=option.radius; var lastpos=pos=0; for ( var i=0;i<data.length;i++){ ctx.beginPath(); ctx.moveTo(cood.x,cood.y); ctx.fillStyle = data[i].bgcolor; pos=lastpos+Math.PI*2*data[i].value/100; ctx.arc(cood.x,cood.y,radius,lastpos,pos,false); ctx.fill(); lastpos=pos; } ctx.beginPath(); ctx.fillStyle = "white" ; radius*=0.5; ctx.arc(cood.x,cood.y,radius,0,Math.PI*2 ,false); ctx.fill(); } var data=[ {bgcolor: 'yellowgreen' ,value:30}, {bgcolor: 'green' ,value:30}, {bgcolor: 'yellow' ,value:40} ]; var canvas = document.getElementById( "myCanvas" ); var ctx = canvas.getContext( "2d" ); yuanhuan(ctx,data,{cood:{x:200,y:200},radius:150}) </script> </body> </html> |
希望本文所述对大家的javascript程序设计有所帮助。
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