匀速运动（速度不整除的方法） 

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>匀速运动</title>
    <style>
        #div1 {
            width: 50px;
            height: 150px;
            background: red;
            position: absolute;
            left: 500px;
        }
        
        span {
            width: 1px;
            height: 300px;
            background: black;
            position: absolute;
            left: 300px;
        }
    </style>
    <script>
        window.onload = function() {
            var oDiv = document.getElementById('div1');
            var oBtn = document.getElementById('btn1');
            oBtn.onclick = function() {
                startMove(300);
            }
        }
        var timer = null;

        function startMove(iTarget) {
            var oDiv = document.getElementById('div1');
            clearInterval(timer);
            timer = setInterval(function() {
                var iSpeed = 0;
                if (oDiv.offsetLeft < iTarget) {
                    iSpeed = 7;
                } else {
                    iSpeed = -7;
                }
                if (Math.abs(oDiv.offsetLeft - iTarget) < 7) {
                    clearInterval(timer);
                    oDiv.style.left = iTarget + 'px';
                } else {
                    oDiv.style.left = oDiv.offsetLeft + iSpeed + 'px';
                }
            }, 30);
        }
    </script>
</head>

<body>
    <input id="btn1" type="button" name="" value="移动" style="margin:10px;">
    <div id="div1"></div>
    <span></span>
</body>

</html>

 

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posted @ 2017-02-16 11:23  Mr_W_Blog  阅读(188)  评论(0)  编辑  收藏  举报