创建HTML文件，CSS文件和JavaScript文件，并引入jquery。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="full-screen" content="yes">
<meta name="browsermode" content="application">
<meta name="x5-orientation" content="portrait">
<title>圆形进度条加载</title>
</head>
<link rel="stylesheet" href="css/circle.css">
<body>
<div class="periphery">
<canvas id="circleCanvas" width="200" height="200"></canvas>
<!--请用img标签添加图片资源进行测试，越多越好，为避免看不到效果请把canvas层级调高-->
<img src='a.jpg'/>
<img src='a.jpg'/>
<img src='a.jpg'/>
<img src='a.jpg'/>
</div>
<script type="text/javascript" src="js/jquery-2.1.0.js" ></script>
<script type="text/javascript" src="js/circle.js" ></script>
</body>
</html>
css样式，自行调整大小或位置
/*初始化页面*/
*{
padding:0;
margin:0;
border:0;
}
body,html{
width:100%;
height:100%;
overflow: hidden;
}
.periphery{
width:100%;
height:100%;
position: relative;
background: #ccc;
}
#circleCanvas{
position: absolute;
top:50%;
left:50%;
transform: translate(-50%,-50%);
}
.periphery img{
opacity: 0;
}
接下来是核心功能实现，采用js绘制并渲染canvas
function drawCircleLoading(ctx,progress){
ctx.clearRect(0,0,200,200);
ctx.beginPath();
ctx.lineWidth=10;
ctx.strokeStyle='rgba(50,207,224,1)';
ctx.arc(100,100,40,0,2 * Math.PI,false);
ctx.stroke();
ctx.beginPath();
ctx.lineWidth=4;
ctx.strokeStyle='rgba(50,207,224,1)';
ctx.arc(100,100,50,0,2 * Math.PI,false);
ctx.stroke();
ctx.beginPath();
ctx.lineWidth=4;
ctx.strokeStyle='rgba(0,0,0,0.2)';
ctx.arc(100,100,50,0,2 * Math.PI,false);
ctx.stroke();
ctx.beginPath();
ctx.save()
ctx.translate(0,200);
ctx.rotate(270 * Math.PI/180);
ctx.lineWidth=10;
ctx.strokeStyle='rgba(0,0,0,0.2)';
ctx.arc(100,100,40,0,1.9999 * Math.PI * (progress * 0.01),true);
ctx.stroke();
ctx.restore();
ctx.beginPath();
ctx.font="18px Arial";
ctx.fillStyle="#0000ff";
ctx.fillText(progress+"%",100 - (ctx.measureText(progress+"%").width) / 2,100 + 6);
ctx.fill();
ctx.closePath();
}
//根据图片load进度条
function loadingAsImgLength(){
//创建Canvas
var c=document.getElementById("circleCanvas");
var ctx=c.getContext("2d");
var precent= -1;
var imglen = $('img').length;
for(var i = 0; i < imglen; i++){
var imgs = new Image();
imgs.src = $('img').eq(i).attr("src");
imgs.onload = function () {
precent= precent+=1;
var num = parseInt((precent/(imglen-1))*100);
var j = num;
(function (j) {
setTimeout(function () {
//开始加载
drawCircleLoading(ctx,j);
console.log(j)
if(j>=100){
j = 100;
drawCircleLoading(ctx,j);
setTimeout(function(){
//这里放加载结束后的操作代码
// alert("over");
},600)
return;
}
},j*20)
})(j)
}
}
}
$(function(){
loadingAsImgLength();
})
注意事项：请保证图片路径正确，并尽可能添加多的img标签来确保看到效果。
最终实现的效果图：
