图片的淡入淡出 

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

<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        #img1 {
            filter: alpha(opacity: 30);
            opacity: 0.3;
        }
    </style>
    <script>
        window.onload = function() {
            var oImg = document.getElementById('img1');
            oImg.onmouseover = function() {
                startMove(100);
            }
            oImg.onmouseout = function() {
                startMove(30);
            }
        }
        var timer = null;
        var alpha = 30;

        var iTarget = null;

        function startMove(iTarget) {
            var oImg = document.getElementById('img1');
            clearInterval(timer);
            timer = setInterval(function() {
                var iSpeed = 0;
                if (alpha < iTarget) {
                    iSpeed = 10;
                } else {
                    iSpeed = -10;
                }
                if (alpha == iTarget) {
                    clearInterval(timer);
                } else {
                    alpha += iSpeed;
                    oImg.style.filter = 'alpha(opacity:' + alpha + ')';
                    oImg.style.opacity = alpha / 100;
                }
            }, 30)
        }
    </script>
</head>

<body>
    <img id="img1" src="bg.jpg" alt="" width="800px">
</body>

</html>

 

查看范例

posted @ 2017-02-15 16:09  Mr_W_Blog  阅读(206)  评论(0)  编辑  收藏  举报