JS 仿腾讯发表微博的效果代码

<div id="msgBox">
        <form>
            <h2>来 , 说说你在做什么 , 想什么</h2>
            <div>
                <input id="userName" class="f-text" value="" />
                <p id="face">
                    <img src="img/face1.gif" class="current" />
                    <img src="img/face2.gif" />
                    <img src="img/face3.gif" />
                    <img src="img/face4.gif" />
                    <img src="img/face5.gif" />
                    <img src="img/face6.gif" />
                    <img src="img/face7.gif" />
                    <img src="img/face8.gif" />
                </p>
            </div>
            <div>
                <textarea id="conBox" class="f-text"></textarea>
            </div>
            <div class="tr">
                <p>
                    <span class="countTxt">还能输入</span><strong class="maxNum">140</strong><span>个字</span>
                    <input id="sendBtn" type="button" value="" title="快捷键 Ctrl+Enter" />
                </p>
            </div>
        </form>
        <div class="list">
            <h3><span>大家在说</span></h3>
            <ul id="list-msg"></ul>
        </div>   
    </div>

body,div,h2,h3,ul,li,p{margin:0;padding:0;}
    a{text-decoration:none;}
    a:hover{text-decoration:underline;}
    ul{list-style-type:none;}
    body{color:#333;background:#3c3a3b;font:12px/1.5 \5b8b\4f53;}
    #msgBox{width:500px;background:#fff;border-radius:5px;margin:10px auto;padding-top:10px;}
    #msgBox form h2{font-weight:400;font:400 18px/1.5 \5fae\8f6f\96c5\9ed1;}
    #msgBox form{background:url(img/boxBG.jpg) repeat-x 0 bottom;padding:0 20px 15px;}
    #userName,#conBox{color:#777;border:1px solid #d0d0d0;border-radius:6px;background:#fff url(img/inputBG.png) repeat-x;padding:3px 5px;font:14px/1.5 arial;}
    #userName.active,#conBox.active{border:1px solid #7abb2c;}
    #userName{height:20px;}
    #conBox{width:448px;resize:none;height:65px;overflow:auto;}
    #msgBox form div{position:relative;color:#999;margin-top:10px;}
    #msgBox img{border-radius:3px;}
    #face{position:absolute;top:0;left:172px;}
    #face img{float:left;display:inline;width:30px;height:30px;cursor:pointer;margin-right:6px;opacity:0.5;filter:alpha(opacity=50);}
    #face img.hover,#face img.current{width:28px;height:28px;border:1px solid #f60;opacity:1;filter:alpha(opacity=100);}
    #sendBtn{border:0;width:112px;height:30px;cursor:pointer;margin-left:10px;background:url(img/btn.png) no-repeat;}
    #sendBtn.hover{background-position:0 -30px;}
    #msgBox form .maxNum{font:26px/30px Georgia, Tahoma, Arial;padding:0 5px;}
    #msgBox .list{padding:10px;}
    #msgBox .list h3{position:relative;height:33px;font-size:14px;font-weight:400;background:#e3eaec;border:1px solid #dee4e7;}
    #msgBox .list h3 span{position:absolute;left:6px;top:6px;background:#fff;line-height:28px;display:inline-block;padding:0 15px;}
    #msgBox .list ul{overflow:hidden;zoom:1;}
    #msgBox .list ul li{float:left;clear:both;width:100%;border-bottom:1px dashed #d8d8d8;padding:10px 0;background:#fff;overflow:hidden;}
    #msgBox .list ul li.hover{background:#f5f5f5;}
    #msgBox .list .userPic{float:left;width:50px;height:50px;display:inline;margin-left:10px;border:1px solid #ccc;border-radius:3px;}
    #msgBox .list .content{float:left;width:400px;font-size:14px;margin-left:10px;font-family:arial;word-wrap:break-word;}
    #msgBox .list .userName{display:inline;padding-right:5px;}
    #msgBox .list .userName a{color:#2b4a78;}
    #msgBox .list .msgInfo{display:inline;word-wrap:break-word;}
    #msgBox .list .times{color:#889db6;font:12px/18px arial;margin-top:5px;overflow:hidden;zoom:1;}
    #msgBox .list .times span{float:left;}
    #msgBox .list .times a{float:right;color:#889db6;}
    .tr{overflow:hidden;zoom:1;}
    .tr p{float:right;line-height:30px;}
    .tr *{float:left;}
    .hidden {display:none;}

/**
 * 仿腾讯发表微博的效果
 * 1.目前没有发ajax请求 后台没有记录 所以刷新页面 会清掉
 * 2. 时间是用的是客户端时间 假如客户端时间错误的话 那么时间也会受影响。
 * 目前就这样交互 具体的思路不太复杂 如果项目中用到这样的 可以根据具体的需求更改
 * @constructor Microblog
 * @date 2013-12-23
 * @author tugenhua
 * @email 879083421@qq.com
 */

 function Microblog(options) {

    this.config = {
        maxNum                        :   140,               // 最大的字符数
        targetElem                    :   '.f-text',         // 输入框 或者文本域的class名
        maxNumElem                    :   '.maxNum',         // 还能输入多少字容器
        sendBtn                       :   '#sendBtn',        // 广播按钮
        face                          :   '#face',           // 表情容器
        activeCls                     :   'active',          // 鼠标点击输入框add类
        currentCls                    :   'current',         // 鼠标点击face头像时 增加的类名
        inputID                       :   '#userName',       // 输入框ID
        textareaId                    :   '#conBox',         // 文本域ID
        list                          :   '#list-msg',       // 大家在说的容器
        callback                      :   null               // 动态广播完后的回调函数
    };

    this.cache = {};
    this.init(options);
 }

 Microblog.prototype = {

    constructor: Microblog,

    init: function(options) {
        this.config = $.extend(this.config,options || {});
        var self = this,
            _config = self.config,
            _cache = self.cache;

        // 点击输入框input 文本域 textarea 边框的变化
        $(_config.targetElem).each(function(index,item){

            $(item).unbind('focus');
            $(item).bind('focus',function(e){
                !$(this).hasClass(_config.activeCls) && $(this).addClass(_config.activeCls);
            });
            $(item).unbind('blur');
            $(item).bind('blur',function(e){
                $(this).hasClass(_config.activeCls) && $(this).removeClass(_config.activeCls);
            });
        });

        // 点击face头像 add(增加)类名
        var faceImg = $('img',$(_config.face));
        $(faceImg).each(function(index,item){
            $(item).unbind('click');
            $(item).bind('click',function(e){
                $(this).addClass(_config.currentCls).siblings().removeClass(_config.currentCls);
            });
        });

        // 广播按钮hover事件
        $(_config.sendBtn).hover(function(){
            !$(this).hasClass('hover') && $(this).addClass('hover');
        },function(){
            $(this).hasClass('hover') && $(this).removeClass('hover');
        })

        // 绑定事件
        self._bindEnv();
    },
    /*
     * 计算字符的长度 包括中文 数字 英文等等
     * @param str
     * @return 字符串的长度
     */
     _countCharacters: function(str) {
         var totalCount = 0;
          for (var i=0; i<str.length; i++) {
             var c = str.charCodeAt(i);
             if ((c >= 0x0001 && c <= 0x007e) || (0xff60<=c && c<=0xff9f)) {
                totalCount++;
             }else {  
                totalCount+=2;
             }
         }
         return totalCount;
     },
     /*
      * 所有的绑定事件
      */
     _bindEnv: function() {
        var self = this,
            _config = self.config,
            _cache = self.cache;

        // 文本域keyup事件
        self._keyUp();

        // 点击广播按钮事件
        self._clickBtn();
     },
     /*
      * 文本域keyup事件
      */
     _keyUp: function() {
         var self = this,
             _config = self.config,
             _cache = self.cache;
         $(_config.textareaId).unbind('keyup');
         $(_config.textareaId).bind('keyup',function(){
             var len = self._countCharacters($(this).val()),
                 html;
             if(_config.maxNum * 1 >= len * 1) {
                html = _config.maxNum * 1 - len * 1;
             }else {
                html = _config.maxNum * 1 - len * 1;
             }
             $(_config.maxNumElem).html(html);
             $(_config.maxNumElem).attr('data-html',html);
         });
     },
     /*
      * 点击广播按钮事件
      */
     _clickBtn: function() {

        var self = this,
            _config = self.config,
            _cache = self.cache;
        var reg = /^\s*$/g;
        $(_config.sendBtn).unbind('click');
        $(_config.sendBtn).bind('click',function(){

            var inputVal = $(_config.inputID).val(),
                textVal = $(_config.textareaId).val(),
                maxNum = $(_config.maxNumElem).attr('data-html');
            if(reg.test(inputVal)) {
                alert('请输入你的姓名');
                return;
            }else if(reg.test(textVal)) {
                alert("随便说点什么吧!");
                return;
            }
            if(maxNum * 1 < 0) {
                alert('字符超过限制 请缩减字');
                return;
            }
            // 本来是要发ajax请求的 但是这边没有后台处理 所以目前只是客户端渲染页面
            self._renderHTML(inputVal,textVal);
        });
     },
     /*
      * 把html结构渲染出来
      */
     _renderHTML: function(inputVal,textVal) {
         var self = this,
             _config = self.config,
             _cache = self.cache;
        var oLi = document.createElement("li"),
            oDate = new Date();
        oLi.innerHTML = '<div class="userPic">' +
                           '<img src="'+self._getSrc()+'" />'+
                        '</div>' +
                        '<div class="content">' +
                            '<div class="userName"><a href="javascript:;">'+inputVal+'</a>:</div>' +
                            '<div class="msgInfo">'+textVal+'</div>' +
                            '<div class="times">'+
                                '<span>'+self._format(oDate.getMonth() + 1) + "\u6708" + self._format(oDate.getDate()) + "\u65e5 " + self._format(oDate.getHours()) + ":" + self._format(oDate.getMinutes())+'</span>'+
                                '<a class="del hidden" href="javascript:;">删除</a>'+
                            '</div>' +
                        '</div>';
        // 插入元素
        if($(_config.list + " li").length > 0) {

            $(oLi).insertBefore($(_config.list + " li")[0]);
            self._animate(oLi);
        }else {

            $(_config.list).append(oLi);
            self._animate(oLi);

        }
        _config.callback && $.isFunction(_config.callback) && _config.callback();

        // 清空输入框 文本域的值
        self._clearVal();

        // hover事件
        self._hover();
     },
     /*
      * 格式化时间, 如果为一位数时补0
      */
    _format: function(str){
        return str.toString().replace(/^(\d)$/,"0$1");
    },
    /*
     * 获取ing src
     * @return src
     */
    _getSrc: function() {
        var self = this,
            _config = self.config,
            _cache = self.cache;
        var faceImg = $('img',$(_config.face));

        for(var i = 0; i < faceImg.length; i++) {
            if($(faceImg[i]).hasClass(_config.currentCls)) {
                return $(faceImg[i]).attr('src');
                break;
            }
        }
    },
    /*
     * 清空值
     */
    _clearVal: function() {
        var self = this,
            _config = self.config,
            _cache = self.cache;

        $(_config.inputID) && $(_config.inputID).val('');
        $(_config.textareaId) && $(_config.textareaId).val('');

    },
    /*
     * hover事件
     */
    _hover: function() {
        var self = this,
            _config = self.config,
            _cache = self.cache;
        $(_config.list + ' li').hover(function(){
            !$(this).hasClass('hover') && $(this).addClass('hover').siblings().removeClass('hover');
            $('.del',$(this)).hasClass('hidden') && $('.del',$(this)).removeClass('hidden');
            var $that = $(this);

            // 删除事件
            $('.del',$that).unbind('click');
            $('.del',$that).bind('click',function(){

                $($that).animate({
                    'opacity' : 0
                },500,function(){
                    $that.remove();   
                });
            });
        },function(){
            $(this).hasClass('hover') && $(this).removeClass('hover');
            !$('.del',$(this)).hasClass('hidden') && $('.del',$(this)).addClass('hidden');
        });

    },
    /*
     * height
     */
     _animate: function(oLi) {
        var self = this;
        var iHeight = $(oLi).height(),
            alpah = 0,
            timer,
            count = 0;
        $(oLi).css({"opacity" : "0", "height" : "0"});

        timer && clearInterval(timer);
        timer = setInterval(function (){
            $(oLi).css({"display" : "block", "opacity" : "0", "height" : (count += 8) + "px"});
            if (count > iHeight){
                    clearInterval(timer);
                    $(oLi).css({ "height" : iHeight + "px"});
                    timer = setInterval(function (){
                        $(oLi).css({"opacity" : alpah += 10});

                        alpah > 100 && (clearInterval(timer), $(oLi).css({"opacity":100}));

                    },30);
                }
            },30);
     }
 };

 // 初始化代码
 $(function(){
    new Microblog({});
 });