图片轮换
模仿qq/163的图片效果，可以指定显示的图片间距，每次显示的图片数量，当切换图片时，根据指定显示的图片张数，自动将当前图片定位到居中的位置。
在调用init()函数时会根据大图显示的图片自动滚动小图，让对应的小图自动居中。
显示图片的位置或者图片说明什么的，自己防止对象，使用图片类库时传递他们的id进入类库构造函数中即可。
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<!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=utf8" /><title>JavaScript 图片滑动切换效果</title><script type="text/javascript">var $ = function(id) {return "string" == typeof id ? document.getElementById(id) : id;};var Extend = function(destination, source) {for (var property in source) {destination[property] = source[property];}return destination;}var CurrentStyle = function(element) {return element.currentStyle || document.defaultView.getComputedStyle(element, null);}var Bind = function(object, fun) {var args = Array.prototype.slice.call(arguments).slice(2);return function() {return fun.apply(object, args.concat(Array.prototype.slice.call(arguments)));}}var Tween = {Quart: {easeOut: function(t, b, c, d) {return - c * ((t = t / d - 1) * t * t * t - 1) + b;}},Back: {easeOut: function(t, b, c, d, s) {if (s == undefined) s = 1.70158;return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b;}},Bounce: {easeOut: function(t, b, c, d) {if ((t /= d) < (1 / 2.75)) {return c * (7.5625 * t * t) + b;} else if (t < (2 / 2.75)) {return c * (7.5625 * (t -= (1.5 / 2.75)) * t + .75) + b;} else if (t < (2.5 / 2.75)) {return c * (7.5625 * (t -= (2.25 / 2.75)) * t + .9375) + b;} else {return c * (7.5625 * (t -= (2.625 / 2.75)) * t + .984375) + b;}}}}//容器对象,滑动对象,切换数量var SlideTrans = function(container, slider, count, options) {this._slider = $(slider);this._container = $(container); //容器对象this._timer = null; //定时器this._count = Math.abs(count); //切换数量this._target = 0; //目标值this._t = this._b = this._c = 0; //tween参数this.Index = 0; //当前索引this.SetOptions(options);this.Auto = !!this.options.Auto;this.Duration = Math.abs(this.options.Duration);this.Time = Math.abs(this.options.Time);this.Pause = Math.abs(this.options.Pause);this.Tween = this.options.Tween;this.onStart = this.options.onStart;this.onFinish = this.options.onFinish;var bVertical = !!this.options.Vertical;this._css = bVertical ? "top": "left"; //方向//样式设置var p = CurrentStyle(this._container).position;p == "relative" || p == "absolute" || (this._container.style.position = "relative");this._container.style.overflow = "hidden";this._slider.style.position = "absolute";this.Change = this.options.Change ? this.options.Change: this._slider[bVertical ? "offsetHeight": "offsetWidth"] / this._count;};SlideTrans.prototype = {//设置默认属性SetOptions: function(options) {this.options = { //默认值Vertical: true,//是否垂直方向（方向不能改）Auto: true,//是否自动Change: 0,//改变量Duration: 50,//滑动持续时间Time: 10,//滑动延时Pause: 2000,//停顿时间(Auto为true时有效)onStart: function() {},//开始转换时执行onFinish: function() {},//完成转换时执行Tween: Tween.Quart.easeOut //tween算子};Extend(this.options, options || {});},//开始切换Run: function(index) {//修正indexindex == undefined && (index = this.Index);index < 0 && (index = this._count - 1) || index >= this._count && (index = 0);//设置参数this._target = -Math.abs(this.Change) * (this.Index = index);this._t = 0;this._b = parseInt(CurrentStyle(this._slider)[this.options.Vertical ? "top": "left"]);this._c = this._target - this._b;this.onStart();this.Move();},//移动Move: function() {clearTimeout(this._timer);//未到达目标继续移动否则进行下一次滑动if (this._c && this._t < this.Duration) {this.MoveTo(Math.round(this.Tween(this._t++, this._b, this._c, this.Duration)));this._timer = setTimeout(Bind(this, this.Move), this.Time);} else {this.MoveTo(this._target);this.Auto && (this._timer = setTimeout(Bind(this, this.Next), this.Pause));}},//移动到MoveTo: function(i) {this._slider.style[this._css] = i + "px";},//下一个Next: function() {this.Run(++this.Index);},//上一个Previous: function() {this.Run(--this.Index);},//停止Stop: function() {clearTimeout(this._timer);this.MoveTo(this._target);}};</script></head><body><style type="text/css">.container, .container img{width:280px; height:200px;} .container{border:1pxsolid #333;} .container img{border:0;}</style><div id="idContainer"><table id="idSlider" border="0" cellpadding="0" cellspacing="0"><tr><td><a href="http://www.cnblogs.com/cloudgamer/archive/2009/01/06/Tween.html"><img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_rt_1.jpg"/></a></td></tr><tr><td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/07/21/ImgCropper.html"><img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_rt_5.jpg"/></a></td></tr><tr><td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/11/17/Drag.html"><img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_rt_3.jpg"/></a></td></tr></table></div><br /><br /><style type="text/css">.num{ position:absolute; right:5px; bottom:5px;} .num li{ float: left;list-style:none; color: #fff; text-align: center; line-height: 16px; width:16px; height: 16px; font-family: Arial; font-size: 12px; cursor: pointer;margin: 1px; border: 1px solid #707070; background-color: #060a0b; } .numli.on{ line-height: 18px; width: 18px; height: 18px; font-size: 14px; border:0; background-color: #ce0609; font-weight: bold; }</style><div id="idContainer2"><table id="idSlider2" border="0" cellpadding="0" cellspacing="0"><tr><td><a href="http://www.cnblogs.com/cloudgamer/archive/2009/03/11/color.html"><img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_4.jpg"/></a></td><td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/12/24/Slider.html"><img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_3.jpg"/></a></td><td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/12/03/Resize.html"><img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_rt_2.jpg"/></a></td></tr></table><ul id="idNum"></ul></div><br /><div><input id="idAuto" type="button" value="停止" /><input id="idPre" type="button" value="<<" /><input id="idNext" type="button" value=">>" /><select id="idTween"><option value="0">默认缓动</option><option value="1">方式1</option><option value="2">方式2</option></select></div><script>new SlideTrans("idContainer", "idSlider", 3).Run();///////////////////////////////////////////////////////////var forEach = function(array, callback, thisObject) {if (array.forEach) {array.forEach(callback, thisObject);} else {for (var i = 0,len = array.length; i < len; i++) {callback.call(thisObject, array[i], i, array);}}}var st = new SlideTrans("idContainer2", "idSlider2", 3, {Vertical: false});var nums = [];//插入数字for (var i = 0,n = st._count - 1; i <= n;) { (nums[i] = $("idNum").appendChild(document.createElement("li"))).innerHTML = ++i;}forEach(nums,function(o, i) {o.onmouseover = function() {o.className = "on";st.Auto = false;st.Run(i);}o.onmouseout = function() {o.className = "";st.Auto = true;st.Run();}})//设置按钮样式st.onStart = function() {forEach(nums,function(o, i) {o.className = st.Index == i ? "on": "";})}$("idAuto").onclick = function() {if (st.Auto) {st.Auto = false;st.Stop();this.value = "自动";} else {st.Auto = true;st.Run();this.value = "停止";}}$("idNext").onclick = function() {st.Next();}$("idPre").onclick = function() {st.Previous();}$("idTween").onchange = function() {switch (parseInt(this.value)) {case 2:st.Tween = Tween.Bounce.easeOut;break;case 1:st.Tween = Tween.Back.easeOut;break;default:st.Tween = Tween.Quart.easeOut;}}st.Run();</script></body></html>