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原生javascript淡入淡出焦点图 + Jquery实现方法

2012-05-13 10:19  VVG  阅读(4654)  评论(4)  编辑  收藏  举报

淡入淡出焦点图效果类

这里是缓动焦点图链接：

JavaScript 缓动焦点图实现的几种写法 封装 + 函数式 + JQuery

焦点图

 

 

实现思路：

原生JS的类的调用方式：

        var slider1 = new Slider({
            id:'focus_pic', /**包裹图片的UL的ID**/
            btnId:"focus_btn", //幻灯片按钮的ID,可以用来控制CSS显示
            //step:5, //透明度变化步长，默认为2
            autoTime:2000//自动播放间隔时间
        });

幻灯片的HTML书写方式：

<ul id="focus_pic">
        <li><a target="_blank" href="javascript:"><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_01.jpg" 
width="530" height="180" alt=""></a></li>
        <li><a target="_blank" href="javascript:"><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_02.jpg" 
width="530" height="180" alt=""></a></li>
        <li><a target="_blank" href="javascript:"><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_03.jpg" 
width="530" height="180" alt=""></a></li>
        <li><a target="_blank" href="javascript:"><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_04.jpg" 
width="530" height="180" alt=""></a></li>
    </ul>

幻灯片的原生JavaScript代码：

<!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"/>
    <title>焦点图</title>
    <style type="text/css">
        #focus_box {
            position: relative;
            margin: 0 auto;
            zoom: 1;
            width: 530px;
            height: 180px;
            overflow: hidden;
        }

        #focus_box ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        #focus_btn {
            position: absolute;
            right: 5px;
            bottom: 5px;
            z-index: 2;
        }

        #focus_pic {
            position: absolute;
        }

        #focus_pic li {
            position: absolute;
            left: 0;
        }

        #focus_pic li img {
            border: none;
            float: left;
        }

        #focus_btn li {
            float: left;
            font-size: 12px;
            width: 25px;
            height: 25px;
            line-height: 25px;
            font-weight: bold;
            text-align: center;
            background: #fff;
            color: #000;
            margin-right: 2px;
            cursor: pointer;
            border-radius: 20px;
        }

        #focus_btn li.on {
            background: #f60;
            color: #fff;
        }

        #focus_box1 {
            position: relative;
            margin: 0 auto;
            overflow: hidden;
            zoom: 1;
        }

        #focus_box1 ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }
    </style>
</head>
<body>
<div id="focus_box">
    <ul id="focus_pic">
        <li><a><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_01.jpg"></a></li>
        <li><a><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_02.jpg"></a></li>
        <li><a><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_03.jpg"></a></li>
        <li><a><img src="http://images.cnblogs.com/cnblogs_com/NNUF/379856/o_04.jpg"></a></li>
    </ul>
</div>
<script type="text/javascript">
    (function () {
        //先设置两个简洁函数获取ID，设置透明度
        var $ = function () {
            var elements = new Array();
            for (var i = 0; i < arguments.length; i++) {
                var element = arguments[i];
                if (typeof element == 'string')
                    element = document.getElementById(element);
                if (!element) continue;
                if (arguments.length == 1) return element;
                elements.push(element);
            }
            return elements;
        };
        var setOpacity = function (node, level) {
            node = $(node);
            if (document.all) {
                node.style.filter = 'alpha(opacity=' + level + ')';
            } else {
                node.style.opacity = level / 100;
            }
        };
        var getTag = function (child, parent) {
            return parent.getElementsByTagName(child);
        };
        var bindEvent = function (element, type, func) {
            if (element.addEventListener) {
                element.addEventListener(type, func, false); //false 表示冒泡
            } else if (element.attachEvent) {
                element.attachEvent('on' + type, func);
            } else {
                element['on' + type] = func;
            }
        };
        function Slider(options) {
            var id = options.id;
            var warper = this.warper = $(id);//获取包裹图片DOM(第一个UL的ID)
            var warpLis = this.warpLis = getTag("li", warper);//获取包裹下的LI子元素
            this.no = warpLis.length;//获取包裹LI元素的个数
            this.step = options.step || 2;
            this.autoTime = options.autoTime || 1000;   //自动播放间隔时间
            this.btnId = options.btnId || "focus_btn"; //图片上面的数字按钮的ID
            this.index = 1; //  开始变幻时的下一个INDEX
            this.preIndex = 0;
            this.init();
        }
        Slider.prototype = {
            init:function () {
                this.makeBtn(this.no, this.btnId);
                this.autoPlay();
            },
            makeBtn:function (no, c) {//生成按钮 no表示个数 C表示UL的ID
                var btnUl = this.btnUl = document.createElement("ul");
                btnUl.id = c;
                for (var i = 0; i < no; i++) {
                    var li = document.createElement('li');
                    if (i == 0) li.className = 'on';
                    var text = document.createTextNode(i + 1);
                    li.appendChild(text);
                    setOpacity(li, 80);
                    // 绑定鼠标事件，传递当前的INDEX和preIndex
                    bindEvent(li, 'mouseover', function (obj, t) {
                        return function () {
                            obj.mouseOn.call(obj, t);
                        }
                    }(this, i));
                    btnUl.appendChild(li);
                }
                this.warper.parentNode.appendChild(btnUl);//添加到父div下
            },
            autoPlay:function(){
                var that = this;
                // 执行播放
                clearTimeout(this.T1);
                this.T1 = setTimeout(function(){that.fadeIn(that.index)},that.autoTime);
            },
            fadeIn:function(index){
                var thisObj = this.warpLis[index];
                var thisOpacity = 0; //当前透明度从0渐入
                var that = this;
                // 底部按钮的同步,与当前的图层Z-index始终在上面
                var btnLi = getTag('li', this.btnUl);
                for (var i = 0, n = btnLi.length; i < n; i++) {
                    btnLi[i].className = '';
                    // 移除所有的Zindex
                    this.warpLis[i].style.zIndex = '';
                }
                //在改变INDEX之前先设置透明度为0
                setOpacity(this.warpLis[index],0);
                // 设置前一个图片的Zindex
                this.warpLis[that.preIndex].style.zIndex = 1;
                // 设置当前图片的Zindex
                this.warpLis[index].style.zIndex = 2;
                btnLi[index].className = 'on';
                //淡入动画
                if(that.T2)clearInterval(that.T2);
                this.T2 = setInterval(function(){
                    setOpacity(thisObj,thisOpacity++);  // 设置透明度渐入
                    if(thisOpacity == 100){
                        thisOpacity = 0;
                        clearInterval(that.T2);
                        that.T2 = null;
                        that.preIndex = that.index ++;
                        if(that.index == that.no)that.index = 0;
                        that.autoPlay();
                    }
                },10);
            },
            mouseOn:function(index){
                this.index = index;
                this.fadeIn(index);
            }
        };
        var slider1 = new Slider({
            id:'focus_pic', /**包裹图片的UL的ID**/
            btnId:"focus_btn", //幻灯片按钮的ID,可以用来控制CSS显示
            //step:5, //透明度变化步长，默认为2
            autoTime:2000//自动播放间隔时间
        });
    })();
</script>
</body>
</html>

用Jquery 方法实现代码：

slider函数的参数解释：id-包裹UL的DIV的id，autoTime-自动播放时间，btn-为是否需要控制按钮，此参数不填即带控制按钮

调用方法：

slider("focus_pic", 3000);//层的ID与自动播放时间

slider("focus_pic", 3000,"noButton"); //幻灯片不带按钮

var slider = function (id, autoTime, btn) {
        var $div = $("#" + id), len = $("li", $div).length;
        var index = 1, timer, preIndex = 0;
        // 初始化
        $div.find("li").css("opacity", 0).eq(0).css("opacity", 1);
        // 生成按钮
        if (!btn) {
            var $dl = $("<dl id='J_flashBtn'></dl>");
            for (var i = 0; i < len; i++) {
                var $dt = $("<dt>" + (i + 1) + "</dt>");
                $dl.append($dt);
            }
            $div.append($dl);
            $dl.find("dt").css("opacity", 0.8).eq(0).addClass("on");
            // 按钮事件
            $dl.find("dt").hover(
                function () {
                    clearInterval(timer);
                    index = $(this).index();
                    $(this).addClass("on").siblings().removeClass("on");
                    auto(index); 
                    preIndex = index;
                }, function () {
                    timer = setInterval(function () {
                        auto(index);
                        preIndex = index++;
                        if (index > len - 1) index = 0;
                    }, autoTime);
                });
        }
        // 循环执行
        timer = setInterval(function () {
            auto(index);
            preIndex = index++;
            if (index > len - 1) index = 0;
        }, autoTime);
        // 主要动画
        function auto(index) {
            $div.find("li").eq(preIndex).css("z-index","0").stop(true, false).animate({opacity:0}, 800);
            $div.find("li").eq(index).css("z-index","1").stop(true, false).animate({opacity:1}, 800);
            if(!btn){
                $dl.find("dt").eq(index).addClass("on").siblings().removeClass("on");
            }
        }
    };