使用css3制作一个简易的环形进度条

话不多说，直接上代码：

css：

section{width:2rem;height:2rem;position: relative;margin:2rem;}
.wrap,.circle,.percent{position: absolute; width: 2rem; height: 2rem; border-radius: 50%;}
.wrap{top:0; left:0; background-color:#ccc;}
.circle{box-sizing: border-box; -webkit-box-sizing:border-box; -ms-box-sizing:border-box; -moz-box-sizing:border-box; -o-box-sizing:border-box; border:1px solid #ccc; clip:rect(0,2rem,2rem,1rem);}
.clip-auto{clip:rect(auto, auto, auto, auto);} .percent{box-sizing: border-box; -webkit-box-sizing:border-box; -ms-box-sizing:border-box; -moz-box-sizing:border-box; -o-box-sizing:border-box; top:-1px; left:-1px;}
.left{border:0.1rem solid #ff6300; clip: rect(0,1rem,2rem,0);} .right{border:0.1rem solid #FF6300; clip: rect(0,2rem,2rem,1rem);}
.wth0{width:0;}
.num{position: absolute; box-sizing: border-box; -webkit-box-sizing:border-box; -ms-box-sizing:border-box; -moz-box-sizing:border-box; -o-box-sizing:border-box; width:1.8rem; height:1.8rem; line-height:1.8rem; text-align: center; font-size: 0.5rem; left:0.1rem; top:0.1rem; border-radius: 50%; color:#FF6300; background: white; z-index: 1;} 

html：

                <!--进度0%-->
		<section>
			<div class="wrap">
				<!--大于180，则class=clip-auto circle，否则：circle-->
				<div class="circle">
					<!--度数为：当前进度*3.6-->
					<div class="percent left" style="-webkit-transform:rotate(0deg);"></div>
					<!--大于180，则class=percent right，否则为percent right wth0-->
					<div class='percent right wth0'></div>
				</div>
				<div class="num">
					<span>0</span>%
				</div>
			</div>
		</section>
		
		<!--进度30%-->
		<section>
			<div class="wrap">
				<!--大于180，则class=clip-auto circle，否则：circle-->
				<div class="circle">
					<!--度数为：当前进度*3.6-->
					<div class="percent left" style="-webkit-transform:rotate(108deg);"></div>
					<!--大于180，则class=percent right，否则为percent right wth0-->
					<div class='percent right wth0'></div>
				</div>
				<div class="num">
					<span>30</span>%
				</div>
			</div>
		</section>
		
		<!--进度50%-->
		<section>
			<div class="wrap">
				<!--大于180，则class=clip-auto circle，否则：circle-->
				<div class="clip-auto circle">
					<!--度数为：当前进度*3.6-->
					<div class="percent left" style="-webkit-transform:rotate(180deg);"></div>
					<!--大于180，则class=percent right，否则为percent right wth0-->
					<div class='percent right'></div>
				</div>
				<div class="num">
					<span>50</span>%
				</div>
			</div>
		</section>
		
		<!--进度70%-->
		<section>
			<div class="wrap">
				<!--大于180，则class=clip-auto circle，否则：circle-->
				<div class="clip-auto circle">
					<!--度数为：当前进度*3.6-->
					<div class="percent left" style="-webkit-transform:rotate(252deg);"></div>
					<!--大于180，则class=percent right，否则为percent right wth0-->
					<div class='percent right'></div>
				</div>
				<div class="num">
					<span>70</span>%
				</div>
			</div>
		</section>
		
		<!--进度100%-->
		<section>
			<div class="wrap">
				<!--大于180，则class=clip-auto circle，否则：circle-->
				<div class="clip-auto circle">
					<!--度数为：当前进度*3.6-->
					<div class="percent left" style="-webkit-transform:rotate(360deg);"></div>
					<!--大于180，则class=percent right，否则为percent right wth0-->
					<div class='percent right'></div>
				</div>
				<div class="num">
					<span>100</span>%
				</div>
			</div>
		</section>

由于demo使用了rem，所以为了看到最好的效果，加上字体调节js

                //自动设置font-zise
		(function (doc, win){
		  var docEl = doc.documentElement,
			resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
			recalc = function(){
			  var clientWidth = docEl.clientWidth;
			  if (!clientWidth) return;
			  docEl.style.fontSize = parseInt(20 * (clientWidth / 320))+ 'px';
			};
		  if (!doc.addEventListener) return;
		  win.addEventListener(resizeEvt, recalc,false);
		  doc.addEventListener('DOMContentLoaded',recalc,false);
		})(document, window);

结果：