日期:2014-05-16  浏览次数:20401 次

求思路,求方法,图片在鼠标滚动放大问题。
最近做一个网站中有一个效果,大家可以把它理解成 谷歌地图,可以拖拽,鼠标滑动放大缩小,只不过是一张图片,有固定的区域大小,超过区域隐藏,基本功能我都实现了,就是有点不完美:
在我鼠标滚动放大缩小的时候都是从左上角开始放大缩小的,我想请问怎么做才能让它以我鼠标所在图片的位置放大缩小呢?
求思路方法

------解决方案--------------------
HTML code

<!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>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="author" content="wangtd"/>
<title>Colors</title>
<style type="text/css">
.container {
    position: relative;
    margin: 100px auto;
    width: 720px;
    height: 450px;
    overflow: hidden;
    border: solid 1px #000000;
}
</style>
</head>

<body>
<div class="container">
    <img id="image" style="position:absolute;top:0;left:0;width:720px;height:450px" src="http://hiphotos.baidu.com/442595744/pic/item/5c0b7d2e0dd722d7023bf63e.jpg" alt=""/>
</div>
<div id="info"></div>
<script type="text/javascript">
var imageHandler = function(id,max,min) {
    var _handler = document.getElementById(id);
    var _moveTop = 0;
    var _moveLeft = 0;
    var _moveFlag = false;
    function startMove() {
        _moveFlag = true;
        var evt = window.event;
        _moveTop = evt.clientY - parseInt(_handler.style.top);
        _moveLeft = evt.clientX - parseInt(_handler.style.left);
    };
    function doMove() {
        if (!_moveFlag) {
            return false;
        }
        var evt = window.event;
        _handler.style.top = evt.clientY - _moveTop + "px";
        _handler.style.left = evt.clientX - _moveLeft + "px";        
    };
    function endMove() {
        _moveFlag = false;
        _handler.releaseCapture();
    };
    function doScale() {
        var evt = window.event;
        var topPercent = (evt.clientY - _handler.getBoundingClientRect().top)/parseInt(_handler.style.height);
        var leftPercent = (evt.clientX - _handler.getBoundingClientRect().left)/parseInt(_handler.style.width);
        if (_handler.scrollWidth + evt.wheelDelta < min || _handler.scrollWidth + evt.wheelDelta > max) {
            return;
        }
        var percent = _handler.scrollHeight/_handler.scrollWidth;
        _handler.style.width = _handler.scrollWidth + evt.wheelDelta + "px";
        _handler.style.height = parseInt(_handler.style.width)*percent + "px";
        
        _handler.style.top = parseInt(_handler.style.top) - topPercent*percent*evt.wheelDelta + "px";
        _handler.style.left = parseInt(_handler.style.left) - leftPercent*evt.wheelDelta + "px";
    };
    
    _handler.onmousedown = startMove;
    _handler.onmousewheel = doScale;
    document.onmousemove = doMove;
    document.onmouseup = endMove;
};
imageHandler("image", 1440, 144);
</script>
</body>
</html>