以下是我们给大家分享是实例代码:
<html> <head> <title>我的第一个 HTML 页面</title> </head> <body> <canvas id='cvs' width='1000' height="800"> </canvas> <script> const cvs =document.getElementById('cvs'); // 计算画布的宽度 const width = cvs.offsetWidth; // 计算画布的高度 const height = cvs.offsetHeight; const ctx = cvs.getContext('2d'); // 设置宽高 cvs.width = width; cvs.height = height; /** ctx:context x,y:偏移 纵横坐标 w:度 h:高 color:颜色 数组,可以把颜色提取出来方便自定义 */ var Cone = function(ctx,x,y,w,h,d,color){ ctx.save(); ctx.translate(x, y); var blockHeight=h; // 中点 var x2 = 0; var y2 = 20; var k2 = 10; var w2 = w; var h2 = h; // 递减度 var decrease = d; ctx.beginPath(); ctx.moveTo(x2+w2,y2); // 椭圆加了边框,所以加1减1 ctx.bezierCurveTo(x2+w2, y2+k2, x2-w2, y2+k2, x2-w2-1, y2); ctx.lineTo(x2-w2+decrease,y2+blockHeight); ctx.bezierCurveTo(x2-w2+decrease, y2+blockHeight+k2, x2+w2-decrease, y2+blockHeight+k2, x2+w2-decrease, y2+blockHeight); ctx.lineTo(x2+w2+1,y2); var linear = ctx.createLinearGradient(x2-w2, y2,x2+w2-decrease, y2+blockHeight); linear.addColorStop(0,color[0]); linear.addColorStop(1,color[1]); ctx.fillStyle = linear ; ctx.strokeStyle=linear ctx.fill(); //ctx.stroke(); ctx.closePath(); //画椭圆 ctx.beginPath(); ctx.moveTo(x2-w2, y2); ctx.bezierCurveTo(x2-w2, y2-k2, x2+w2, y2-k2, x2+w2, y2); ctx.bezierCurveTo(x2+w2, y2+k2, x2-w2, y2+k2, x2-w2, y2); var linear = ctx.createLinearGradient(x2-w2, y2,x2+w2-decrease, y2+blockHeight); linear.addColorStop(1,color[0]); linear.addColorStop(0,color[1]); ctx.fillStyle = linear ; ctx.strokeStyle=linear ctx.closePath(); ctx.fill(); ctx.stroke(); ctx.restore(); }; function dr(m){ const colorList =[ { color:['#76e3ff','#2895ea'], height:60 }, { color:['#17ead9','#5d7ce9'], height:30 }, { color:['#1ca5e5','#d381ff'], height:40 }, { color:['#ffa867','#ff599e'], height:70 }, { color:['#ffa6e3','#ec6a70'], height:50 }, { color:['#f9c298','#d9436a'], height:30 }, { color:['#eb767b','#9971dc'], height:30 }, { color:['#f06af9','#5983ff'], height:100 }, ]; const space = 20; let coneHeight = 0; // 间隔 const gap = 20; const x = 380; const y = 20; const angle = 30; let coneWidth=0; colorList.forEach((item)=>{ coneHeight += item.height +space; }); // 最下面的先画(层级) colorList.reverse().forEach((item,index)=>{ const decrease =Math.tan(Math.PI*angle/180)*(item.height+space); coneWidth=coneWidth + decrease; coneHeight = coneHeight-item.height - space; //圆锥 Cone(ctx,x,coneHeight ,coneWidth ,item.height,decrease,item.color); // 中点 const cX =parseInt(x)+0.5; const cY = parseInt(coneHeight + space+ item.height/2)+0.5; //文字 ctx.save(); ctx.translate(cX , cY ); ctx.textBaseline='top'; ctx.textAlign='center'; const fontSize = item.height/2>=40"//img.jbzj.com/file_images/article/201712/201712130916003.png" alt="" />