圓環倒計時我們經常見到，實現的方法也有很多種。但是本文將介紹一種全新的實現方式，使用SVG來實現倒計時功能。
本文主要用到了SVG的stroke-dasharray和stroke-dashoffset特性。下圖是倒計時運行效果：
SVG倒計時案例
下面說說相關的實現代碼。css實現代碼如下：
svg { transform: rotate(-0.05deg);}circle { transition: stroke-dasharray .2s;}.time-count-x { line-height: 1.5; position: relative;}.time-second { position: absolute; top: 50%; left: 0; right: 0; margin-top: -.75em; text-align: center; font-size: 100px;}相關html代碼如下：
<div id="timeCountX" class="time-count-x"> <svg width="440" height="440" viewBox="0 0 440 440" class="center"> <defs> <linearGradient x1="1" y1="0" x2="0" y2="0" id="gradient1"> <stop offset="0%" stop-color="#e52c5c"></stop> <stop offset="100%" stop-color="#ab5aea"></stop> </linearGradient> <linearGradient x1="1" y1="0" x2="0" y2="0" id="gradient2"> <stop offset="0%" stop-color="#4352f3"></stop> <stop offset="100%" stop-color="#ab5aea"></stop> </linearGradient> </defs> <g transform="matrix(0,-1,1,0,0,440)"> <circle cx="220" cy="220" r="170" stroke-width="50" stroke="#f0f1f5" fill="none" stroke-dasharray="1069 1069"></circle> <circle cx="220" cy="220" r="170" stroke-width="50" stroke="url('#gradient1')" fill="none" stroke-dasharray="1069 1069"></circle> <circle cx="220" cy="220" r="170" stroke-width="50" stroke="url('#gradient2')" fill="none" stroke-dasharray="534.5 1069"></circle> </g> </svg> <span id="timeSecond" class="time-second"></span></div>最后是相關JavaScript代碼：
var eleCircles=document.querySelectorAll("#timeCountX circle");var eleTimeSec=document.getElementById("timeSecond");var perimeter=Math.PI*2*170;var circleInit=function(){ if(eleCircles[1]){ eleCircles[1].setAttribute("stroke-dasharray","1069 1069") } if(eleCircles[2]){ eleCircles[2].setAttribute("stroke-dasharray",perimeter/2+" 1069") } eleTimeSec.innerHTML=""};var timerTimeCount=null;var fnTimeCount=function(b){ if(timerTimeCount){ return } var b=b||10; var a=function(){ var c=b/10; if(eleCircles[1]){ eleCircles[1].setAttribute("stroke-dasharray",perimeter*c+" 1069") } if(eleCircles[2]&&b<=5){ eleCircles[2].setAttribute("stroke-dasharray",perimeter*c+" 1069") } if(eleTimeSec){ eleTimeSec.innerHTML=b } b--; if(b<0){ clearInterval(timerTimeCount); timerTimeCount=null; alert("時間到！"); circleInit() } }; a(); timerTimeCount=setInterval(a,1000)};fnTimeCount();整個案例的代碼非常少，有喜歡的朋友可以將代碼保存到html中，運行一下，體驗體驗實際效果。
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VeVb武林網。
新聞熱點
疑難解答
