画饼图,废话不多说,直接上代码和效果图
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>绘制弧线</title> <style type="text/css"> canvas{ border:1px solid #f00; } </style> </head> <body> <canvas id="myCanvas" width="400" height="300">您的浏览器不支持canvas标签</canvas> <script type="text/javascript"> var canvas=document.getElementById("myCanvas"); function drawCircle(color,beginPoint,radian){ var ctx=canvas.getContext("2d"); ctx.beginPath(); ctx.strokeStyle=color; var circle={ x:100, y:100, r:50 }; ctx.arc(circle.x,circle.y,circle.r,beginPoint,radian,false);//此处按照顺时针画饼 ctx.lineWidth=50; ctx.stroke(); }; if(canvas.getContext){ drawCircle("blue",0,Math.PI*0.1); drawCircle("red",Math.PI*0.1,Math.PI*(0.5+0.1));//此处需要弧度的首尾相接 drawCircle("yellow",Math.PI*(0.5+0.1),Math.PI*(0.5+0.1+1)); drawCircle("orange",Math.PI*(0.5+0.1+1),Math.PI*(0.4+0.5+0.1+1)); } </script> </body> </html>
效果图
时间: 2024-10-10 05:38:24