基础

事件对象 oEvent

var funMou = function(event) {
    var oEvent = event || window.event;

}

oEvent.screenX　　鼠标在电脑屏幕内的水平位置
oEvent.screenY　　鼠标在电脑屏幕内的竖直位置

oEvent.clientX 　　鼠标在可见区内的水平位置
oEvent.clientY　　 鼠标在可见区内的竖直位置

oEvent.pageX　　　  鼠标在网页内的水平位置
oEvent.pageY　　　  鼠标在网页内的竖直位置

 
放大镜

结构

<div id="box" class="box">
    <div class="small">
        <img src="http://www.1mr.cn/news/uppic/502223201095748_2.gif" alt="">
        <div class="mask"></div>
    </div>
    <div class="big">
        <img src="http://www.1mr.cn/news/uppic/502223201095748_2.gif" alt="">
    </div>
</div>

样式
* {
    margin: 0;
    padding: 0;
}
img {
    vertical-align: top;
}
.box {
    position: relative;
     200px;
    height: 267px;
    margin: 100px auto;
    background: #e76345 url("") no-repeat right center;
}
.box .small {
    overflow: hidden;
}
.box .small img{
     200px;
    border-radius: 20px;
}
.box .small .mask{
    position: absolute;
    left: 0;
    top: 0;
     50px;
    height: 50px;
    background: rgba(188, 255, 194, 0.6) url("") no-repeat right center;
    cursor: move;
    display: none;
}
.box .big {
    position: absolute;
    left: 210px;
    top: 0;
     200px;
    height: 200px;
    overflow: hidden;
    display: none;
}
.box .big img{
    position: absolute;
    left: 0;
    top: 0;
     800px;
}

行为

window.onload = function () {
    var oBox = document.getElementById("box");
    var oSmall = oBox.getElementsByClassName("small")[0];
    var oMask = oSmall.getElementsByClassName("mask")[0];
    var oBig = oBox.getElementsByClassName("big")[0];
    var oBigImg = oBig.getElementsByTagName("img")[0];

    oSmall.onmouseover = function () {
        oMask.style.display = "block";
        oBig.style.display = "block";
    }
    oSmall.onmouseout = function () {
        oMask.style.display = "none";
        oBig.style.display = "none";
    }
    var x= 0,y=0;
    oSmall.onmousemove = function (event) {
        var oEvent = event || window.event;
        x = oEvent.clientX-this.offsetParent.offsetLeft-oMask.offsetWidth*0.5;
        y = oEvent.clientY-this.offsetParent.offsetTop-oMask.offsetHeight*0.5;
        x<=0?x=0:(x>=150?x=150:x);
        y<=0?y=0:(y>=217?y=217:y);
        oMask.style.left = x+"px";
        oMask.style.top = y+"px";
　　　　var pars = oBig.offsetWidth/oMask.offsetWidth;
　　　　oBigImg.style.left = -x*pars+"px";
　　　　oBigImg.style.top = -y*pars+"px";
    }
}

 
加载条

结构

<div id="box" class="box">
    <div class="mask"></div>
    <div class="bar"></div>
</div>

样式

* {
    margin: 0;
    padding: 0;
}
.box {
    position: relative;
     400px;
    height: 10px;
    margin: 100px auto;
    background: #e76345 url("") no-repeat right center;
}
.box .mask {
    position: absolute;
    left: 0;
    top: 0;
     0;
    height: 10px;
    background: #e5e76b url("") no-repeat right center;
}
.box .bar {
    position: absolute;
    left: 0;
    top: -5px;
     8px;
    height: 20px;
    cursor: pointer;
    background: #70e780 url("") no-repeat right center;
}

行为

window.onload = function () {
    /**
     * 禁止选中文本（兼容写法）
     **/
    function funClearSelection() {
        window.getSelection?window.getSelection().removeAllRanges():document.selection.empty();
    }
    var oBox = document.getElementById("box");
    var oMask = oBox.getElementsByClassName("mask")[0];
    var oBar = oBox.getElementsByClassName("bar")[0];
    var nMax = oBox.offsetWidth-oBar.offsetWidth;
    oBar.onmousedown = function (event) {
        var oEvent = event || window.event;
        var nSpark = oEvent.clientX-this.offsetLeft;
        var that = this;
        document.onmousemove = function (event) {
            var oEvent = event || window.event;
            var nX = oEvent.clientX-nSpark;
            nX<=0?nX=0:(nX>=nMax?nX=nMax:nX);
            oMask.style.width = nX+"px";
            that.style.left = nX+"px";
            funClearSelection();
        }
        document.onmouseup = function (event) {
            document.onmousemove = null;
            console.log(oMask.offsetWidth/nMax);
        }
    }
}