使用原生JS实现弹出层特效

_createCover: function() {

      var newMask = document.createElement("div");

      newMask.id = this._mark;

      newMask.style.position = "absolute";

      newMask.style.zIndex = "100";

      _scrollWidth = Math.max(document.body.scrollWidth,document.documentElement.scrollWidth);

      _scrollHeight = Math.max(document.body.scrollHeight,document.documentElement.scrollHeight);

      newMask.style.width = _scrollWidth + "px";

      newMask.style.height = _scrollHeight + "px";

      newMask.style.top = "0px";

      newMask.style.left = "0px";

      newMask.style.background = "#000";

      newMask.style.filter = "alpha(opacity=50)";

      newMask.style.opacity = "0.50";

      newMask.style.display = 'none';

      document.body.appendChild(newMask);

      this._cover = newMask;

  }

_createFloater: function(html) {

      var newDiv = document.createElement("div");

      newDiv.id = this._id;

      newDiv.style.position = "absolute";

      newDiv.style.zIndex = "9999";

      newDivWidth = 400;

      newDivHeight = 200;

      newDiv.style.width = newDivWidth + "px";

      newDiv.style.height = newDivHeight + "px";

      newDiv.style.top = (document.body.scrollTop + document.body.clientHeight/2 - newDivHeight/2) + "px";

      newDiv.style.left = (document.body.scrollLeft + document.body.clientWidth/2 - newDivWidth/2) + "px";

      newDiv.style.padding = "5px";

      newDiv.style.display = 'none';

      newDiv.innerHTML = html;

      document.body.appendChild(newDiv);

      this._floater = newDiv;

  }

addjustPosition: function() {

         this._floater.style.top = (document.body.scrollTop + document.body.clientHeight/2 - newDivHeight/2) + "px";

         this._floater.style.left = (document.body.scrollLeft + document.body.clientWidth/2 - newDivWidth/2) + "px";

     }

this._fS = BindAsEventListener(this, this.addjustPosition);

addEventHandler(window, "scroll", this._fS);

// 隐藏后需

removeEventHandler(window, "scroll", this._fS);

var Floater = (function(){

 var me = Class.create();

 me.prototype = {

     initialize: function(options) {

         this._fS = BindAsEventListener(this, this.addjustPosition);

         this.setOptions(options);

     },

     setOptions: function(options) {

         this.options = options || {};

         this._id = options.id;

         this._mark = 'mark';

     },

     show: function(html,options) {

         options = options || {};

         if(!this._cover){

             this._createCover();

         }

         if(!this._floater){

             this._createFloater(html);

         }

         if(options.saveOpt){

             this._saveOption = options.saveOpt;

             this.bindSaveEvent();

         }

         this._bindScrollEvent();

         this.addjustPosition();

         this._floater.style.display = '';

         this._cover.style.display = '';

         this.isShow = true;

     },

     insert: function(html,opts,att){

         var _e = document.createElement("div"), _t;

         _e.innerHTML = html;

         for(var k in opts){

             _e[k] = opts[k];

         }

         _t = this._floater.querySelector('['+att+']');

         if(_t){

             _t.appendChild(_e);

         }

     },

     getFloater: function(){

         if(this._floater){

             return this._floater;

         }

     },

     //遮罩层

     _createCover: function() {

         var newMask = document.createElement("div");

         newMask.id = this._mark;

         newMask.style.position = "absolute";

         newMask.style.zIndex = "100";

         _scrollWidth = Math.max(document.body.scrollWidth,document.documentElement.scrollWidth);

         _scrollHeight = Math.max(document.body.scrollHeight,document.documentElement.scrollHeight);

         newMask.style.width = _scrollWidth + "px";

         newMask.style.height = _scrollHeight + "px";

         newMask.style.top = "0px";

         newMask.style.left = "0px";

         newMask.style.background = "#000";

         newMask.style.filter = "alpha(opacity=50)";

         newMask.style.opacity = "0.50";

         newMask.style.display = 'none';

         document.body.appendChild(newMask);

         this._cover = newMask;

     },

     //新弹出层

     _createFloater: function(html) {

         var newDiv = document.createElement("div");

         newDiv.id = this._id;

         newDiv.style.position = "absolute";

         newDiv.style.zIndex = "9999";

         newDivWidth = 400;

         newDivHeight = 200;

         newDiv.style.width = newDivWidth + "px";

         newDiv.style.height = newDivHeight + "px";

         newDiv.style.top = (document.body.scrollTop + document.body.clientHeight/2 - newDivHeight/2) + "px";

         newDiv.style.left = (document.body.scrollLeft + document.body.clientWidth/2 - newDivWidth/2) + "px";

         newDiv.style.padding = "5px";

         newDiv.style.display = 'none';

         newDiv.innerHTML = html;

         document.body.appendChild(newDiv);

         this._floater = newDiv;

     },

     //弹出层滚动居中

     addjustPosition: function() {

         this._floater.style.top = (document.body.scrollTop + document.body.clientHeight/2 - newDivHeight/2) + "px";

         this._floater.style.left = (document.body.scrollLeft + document.body.clientWidth/2 - newDivWidth/2) + "px";

     },

     bindSaveEvent: function() {

         this._saveElem = this._floater.querySelector('['+this._saveOption.elem+']');

         if(this._saveElem){

             addEventHandler(this._saveElem, "click", this._saveOption.handler);

         }

     },

     _bindScrollEvent: function() {

         addEventHandler(window, "scroll", this._fS);

     },

     hide: function() {

         this.isShow = false;

         this.destory();

     },

     destory: function() {

         removeEventHandler(window, "scroll", this._fS);

         if(this._saveElem){

             removeEventHandler(this._saveElem, "click", this._saveOption.handler);

         }

         if (this._cover){

             document.body.removeChild(this._cover);

         }

         if (this._floater){

             document.body.removeChild(this._floater);

         }

         this._cover = null;

         this._floater = null;

     }

 };

 return me;

 })();