【JavaScript】放大镜效果

时间：2023-02-02 15:08:30
<!DOCTYPE html>

<html lang="en">

<head>

	<meta charset="UTF-8">

	<title>放大镜</title>

	<style type="text/css">

	*{margin:0;padding:0;}

	.container{width: 200px;height: 200px;padding: 5px;border:1px solid #CCC;position: relative;left: 50px;top: 50px;}

	.container .small_pic{width: 200px;height: 200px;background: #ccc;position: relative;}

	.container .float_layer{width: 50px;height: 50px;border:1px solid #000;background: #fff;filter:alpha(opacity: 30);opacity: 0.3;position: absolute;top: 0;left: 0;z-index: 1;display: none;}

	.container .mask{width: 100%;height: 100%;position: absolute;z-index: 2;left: 0;top: 0;background: red;filter:alpha(opacity: 0);opacity: 0;}

	.container .big_pic{position: absolute;top: -1px;left: 215px;width: 250px;height: 250px;overflow: hidden;display: none;border:2px solid #ccc;}

	.container img{position: absolute;top: 0;left: 0;}

	</style>

</head>

<body>

	<div class="container"  id="div1">

		<div class="small_pic">

			<span class="mask"></span>

			<span class="float_layer"></span>

			<img src="http://b.hiphotos.baidu.com/image/w%3D310/sign=6c8629c441540923aa69657fa259d1dc/b812c8fcc3cec3fd1d347092de88d43f869427cb.jpg" />

		</div>

		<div class="big_pic">

			<img src="http://a.hiphotos.baidu.com/image/w%3D310/sign=c53e905c4f10b912bfc1f0fff3fcfcb5/83025aafa40f4bfbf3c249b30b4f78f0f63618c2.jpg" />

		</div>

	</div>

	<script type="text/javascript">

	var util = {			//获取类名

		getByClass : function(oParent,oClass){

			var oEle = oParent.getElementsByTagName('*');

			var oTemp = [];

			for(var i = 0 ; i < oEle.length ; i++){

				if(oEle[i].className == oClass){

					oTemp.push(oEle[i]);

				}

			}

			return oTemp;

		}

	}

	window.onload = function(){

		var oDiv = document.getElementById('div1');

		var oMask = util.getByClass(oDiv,'mask')[0];

		var oFloat = util.getByClass(oDiv,'float_layer')[0];

		var oBig = util.getByClass(oDiv,'big_pic')[0];

		var oSamll = util.getByClass(oDiv,'small_pic')[0];

		var oImg = oBig.getElementsByTagName('img')[0];

		oMask.onmouseover = function(){

			oFloat.style.display = "block";

			oBig.style.display = "block";

		}

		oMask.onmouseout = function(){

			oFloat.style.display = "none";

			oBig.style.display = "none";

		}

		oMask.onmousemove = function(e){

			var e = e || window.event;

			var oLeft = e.clientX - oDiv.offsetLeft - oSamll.offsetLeft - oFloat.offsetWidth / 2;		//灰色遮罩层偏移量

			var oTop = e.clientY - oDiv.offsetTop - oSamll.offsetTop - oFloat.offsetHeight / 2;

			if(oLeft < 0){			//边缘判断

				oLeft = 0;

			}else if(oLeft > oMask.offsetWidth - oFloat.offsetWidth){

				oLeft = oMask.offsetWidth - oFloat.offsetWidth;

			}

			if(oTop < 0){

				oTop = 0;

			}else if(oTop > oMask.offsetHeight - oFloat.offsetHeight){

				oTop = oMask.offsetHeight - oFloat.offsetHeight;

			}

			oFloat.style.left = oLeft + 'px';

			oFloat.style.top = oTop + 'px';

			var oPercentX = oLeft / (oMask.offsetWidth - oFloat.offsetWidth);			//两图比例计算

			var oPercentY = oTop / (oMask.offsetHeight - oFloat.offsetHeight);

			oImg.style.left = -oPercentX * (oImg.offsetWidth - oBig.offsetWidth) + 'px';		//最终大图所处位置

			oImg.style.top = -oPercentY * (oImg.offsetHeight - oBig.offsetHeight) + 'px';

		}

	}

	</script>

</body>

</html>

可复制下来直接使用

比较简单放大镜效果

相关文章