1、css代码
此处在制作进度条时，是旋转进度条的半圆（红色），背景使用灰白（如果使用红色作为背景，旋转灰白遮罩，在浏览器中可能会有渲染bug）
.wrapper{ display:block;position:relative;width:100px;height:100px;border-radius:50px;overflow:hidden; }
.pie { position:absolute;background-color:#e74c3c;width:100px;height:100px; }
.pie1 { clip:rect(0px,50px,100px,0px); }
.pie2 { clip:rect(0px,100px,100px,50px); }
.hold { width:100px;height:100px;position:absolute;z-index:; }
.hold1 { clip:rect(0px,100px,100px,50px); }
.hold2 { clip:rect(0px,50px,100px,0px); }
.bg { width:100px;height:100px;background-color:#f4f6f6;position:absolute; }
.circle{position:absolute;background-color:#FFF;width:90px;height:90px;border-radius:45px;left:5px;top:5px;z-index:;}
以下的css的代码会产生渲染bug（导致灰白外侧有红色细线）
.wrapper{ display:block;position:relative;width:100px;height:100px;border-radius:50px;overflow:hidden; }
.pie { position:absolute;background-color:#f4f6f6;width:100px;height:100px; }
.pie1 { clip:rect(0px,100px,100px,50px); }
.pie2 { clip:rect(0px,50px,100px,0px); }
.hold { width:100px;height:100px;position:absolute;z-index:; }
.hold1 { clip:rect(0px,100px,100px,50px); }
.hold2 { clip:rect(0px,50px,100px,0px); }
.bg { width:100px;height:100px;background-color:#e74c3c;position:absolute; }
.circle{position:absolute;background-color:#FFF;width:90px;height:90px;border-radius:45px;left:5px;top:5px;z-index:;}
2、html代码
<div class="wrapper">
<div class="hold hold1">
<div class="pie pie1"></div>
</div>
<div class="hold hold2">
<div class="pie pie2"></div>
</div>
<div class="bg"></div>
<div class="circle"></div>
</div>
<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
3、js代码
var pie = {
run:function(opts){
if(!opts.pie1 || !opts.pie2) throw new Error('must be element pie1 and pie2.');
var pie1 = $(opts.pie1), pie2 = $(opts.pie2);
var percent = opts.percent || 0;
var step = opts.step || 3;
var delay = opts.delay || 50;
var callback = opts.callback || $.noop;
var i = 0, rage = 360 * percent;
var djs = function(){
i = i + step;
if(i <= rage){
if(i <= 180){
if((180 - i) < step){ i = 180; }
pie1.css("-webkit-transform","rotate(" + i + "deg)");
} else {
if((rage - i) < step){ i = rage; }
pie2.css("-webkit-transform","rotate(" + (i-180) + "deg)");
}
callback(i, rage);
setTimeout(djs, delay);
}
};
djs();
}
};
pie.run({
pie1:".pie1",
pie2:".pie2",
percent:0.75
});
参考demo：http://liumiao.me/demo/count/
最新Canvas版
.jqm-round-wrap{
display:block;position:relative;width:130px;height:130px;overflow:hidden;
border-radius:65px;
-webkit-border-radius:65px;
}
#jqm-round-sector{
position:absolute;width:130px;height:130px;
}
.jqm-round-bg {
position:absolute;width:130px;height:130px;background-color:#f4f6f6;
border-radius:65px;
-webkit-border-radius:65px;
}
.jqm-round-circle{
position:absolute;background-color:#FFF;width:120px;height:120px;left:5px;top:5px;z-index:;
border-radius:60px;
-webkit-border-radius:60px;
}
<div class="jqm-round-wrap">
<div class="jqm-round-bg"></div>
<canvas id="jqm-round-sector"></canvas>
<div class="jqm-round-circle">15<samp>%</samp></div>
</div>
var pie = {
run:function(opts){
if(!opts.id) throw new Error("must be canvas id.");
var canvas = document.getElementById(opts.id), ctx;
if(canvas && (ctx = canvas.getContext("2d"))){
canvas.width = canvas.height = "200";
var noop = function(){};
var before = opts.onBefore || noop;
var after = opts.onAfter || noop;
before(ctx);
ctx.fillStyle = opts.color || '#f4f6f6';
var step = opts.step || 1;
var delay = opts.delay || 10;
var i = 0, rage = 360 * (opts.percent || 0);
var sRage = -Math.PI * 0.5;
var djs = function(){
i = i + step;
if(i <= rage){
ctx.beginPath();
ctx.moveTo(100, 100);
ctx.arc(100, 100, 100, sRage, Math.PI * 2 * (i/360)+sRage);
ctx.fill();
setTimeout(djs, delay);
} else {
after(ctx);
}
};
djs();
}
}
};
pie.run({
id:"jqm-round-sector",
percent:0.75,
onBefore:function(ctx){
ctx.fillStyle = '#47b28b';
ctx.beginPath();
ctx.moveTo(100, 100);
ctx.arc(100, 100, 100, 0, Math.PI * 2);
ctx.fill();
}
});