canvas光晕

canvas光晕-LMLPHP
 <!DOCTYPE html>

 <html>

     <head>

         <meta charset="utf-8">

         <title></title>

         <script type="text/javascript">

             function draw(id){

                 var convas = document.getElementById(id);

                 if(canvas == null){

                     return false;

                 }

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

                 context.fillStyle = '#eeeeff';

                 context.fillRect(0,0,400,300);

                 for(var i=0;i<10;i++){

                     context.beginPath();

                     context.arc(i*25,i*25,i*10,0,Math.PI*2,true);

                     context.closePath();

                     context.fillStyle = 'rgba(255,0,0,0.25)';

                     context.fill();

                 }

             }

         </script>

     </head>

     <body onload="draw('canvas');">

         <canvas id="canvas" width="400" height="300"></canvas>

     </body>

 </html>