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js學習總結----動畫之在指定時間內實現單方向勻速運動

mar eight 思想 offset line ack css += hang

具體代碼如下

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        *{
            margin:0;
            padding:0;
        }
        #box{
            position:absolute;
            top:0;
            left:
0; padding:0; width:100px; height:100px; background:lightblue; } </style> </head> <body> <div id=‘box‘></div> <script> //思想1: var oBox = document.getElementById(‘box‘); //實現一個勻速運動:在指定時間內完成動畫:計算出總距離/總時間,然後求出對應的步長(每10ms走一步的話需要走多遠)
var maxLeft = (document.documentElement.clientWidth || document.body.clientWidth) - oBox.offsetWidth; var duration = 2000; var step = (maxLeft/duration)*10; var timer = window.setInterval(function(){ var curLeft = utils.css(oBox,"left"); curLeft+=step;
if(curLeft>=maxLeft){ window.clearInterval(timer); return; } utils.css(oBox,"left",curLeft); },10) //思想2: function Linear(t,b,c,d){//相對應的是time begin change duration return c*t/d+b } var oBox = document.getElementById(‘box‘); var target = (document.documentElement.clientWidth || document.body.clientWidth) - oBox.offsetWidth; var begin = utils.css(oBox,‘left‘),change = target-begin; var duration = 2000,time = null; var timer = window.setInterval(function(){ time+=10; if(time>=duration){ utils.css(oBox,"left",target); window.clearInterval(timer); return; } var curPos = Linear(time,begin,change,duration); utils.css(oBox,"left",curPos) },10) </script> </body> </html>

js學習總結----動畫之在指定時間內實現單方向勻速運動