动画函数封装：每0.02s移动10px
<!doctype html> <html lang="en"> <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 http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <style> div{ width: 200px; height: 200px; background-color: red; /*脱离文档流*/ position: absolute; } </style> <script> // 设置任意的一个元素，移动到指定的目标位置 function animate(element,target) { clearInterval(element.timeId); // 定时器的id值存储在对象的一个属性中 element.timeId=setInterval(function () { // 获取元素的当前位置，数字类型 var current=element.offsetLeft; // 每次移动的距离 var step=10; step=current<target?step:-step; // 当前移动到位置 current +=step; if (Math.abs(current-target)>Math.abs(step)){ element.style.left=current+"px"; } else { // 清理定时器 clearInterval(element.timeId); // 直到到达目标 element.style.left=target+"px"; } }),20); } </script> </head> <body> </body> </html>
案例：匀速运动
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>title</title> <style> * { margin: 0; padding: 0; } div { margin-top: 20px; width: 200px; height: 100px; background-color: green; position: absolute; left: 0; top: 0; } </style> </head> <body> <input type="button" value="移动到400px" id="btn1"/> <input type="button" value="移动到800px" id="btn2"/> <div id="dv"> <script src="common.js"></script> <script> //点击按钮移动div my$("btn1").onclick = function () { animate(my$("dv"), 400); }; my$("btn2").onclick = function () { animate(my$("dv"), 800); }; //匀速动画 function animate(element, target) { //清理定时器 clearInterval(element.timeId); element.timeId = setInterval(function () { //获取元素的当前位置 var current = element.offsetLeft; //移动的步数 var step = 10; step = target > current ? step : -step; current += step; if (Math.abs(current - target) > Math.abs(step)) { element.style.left = current + "px"; } else { clearInterval(element.timeId); element.style.left = target + "px"; } }, 20); } </script> </div> </body> </html>
案例：变速运动动画
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>变速</title> <style> * { margin: 0; padding: 0; } div { margin-top: 20px; width: 200px; height: 100px; background-color: green; position: absolute; left: 0; top: 0; } </style> </head> <body> <input type="button" value="移动到400px" id="btn1"/> <input type="button" value="移动到800px" id="btn2"/> <div id="dv"> <script src="common.js"></script> <script> //点击按钮移动div my$("btn1").onclick = function () { animate(my$("dv"), 400); }; my$("btn2").onclick = function () { animate(my$("dv"), 800); }; //匀速动画 function animate(element, target) { //清理定时器 clearInterval(element.timeId); element.timeId = setInterval(function () { //获取元素的当前位置 var current = element.offsetLeft; //移动的步数 var step = (target-current)/10; //Math对象方法 ceil 向上取整 floor 向下取整 step = step>0?Math.ceil(step):Math.floor(step); current += step; element.style.left = current + "px"; if(current==target) { //清理定时器 clearInterval(element.timeId); } //测试代码: console.log("目标位置:"+target+",当前位置:"+current+",每次移动步数:"+step); }, 20); } </script> </div> </body> </html>
