js生成缩略图

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <script type="text/javascript" language="javascript">
        var flag = false;
        function DrawImage(ImgD) {            
            var image = new Image();
            image.src = ImgD.src;
            if (image.width > 0 && image.height > 0) {
                flag = true;
                if (image.width / image.height >= 164 / 112) {
                    if (image.width > 164) {
                        ImgD.width = 164;
                        ImgD.height = (image.height * 164) / image.width;
                    } else {
                        ImgD.width = image.width;
                        ImgD.height = image.height;
                    }
                    ImgD.alt = image.width + "×" + image.height;
                }
                else {
                    if (image.height > 35) {
                        ImgD.height = 35;
                        ImgD.width = (image.width * 35) / image.height;
                    } else {
                        ImgD.width = image.width;
                        ImgD.height = image.height;
                    }
                    ImgD.alt = image.width + "×" + image.height;
                }
            }
        }
    </script>
</head>
<body>
    <input type="button" value="生成缩略图" onclick="DrawImage(this.nextSibling)" /><img src="img/0.jpg" border="0" width="164" height="112" >
</body>
</html>

posted @ 2011-12-02 09:22  小女阿媚  阅读(1592)  评论(0)  编辑  收藏  举报