百度地图自定义覆盖物

Question

var mp = new BMap.Map("allmap",{minZoom:16,maxZoom:19,enableMapClick: false});    mp.centerAndZoom(new BMap.Point(114.324421,30.534198), 15);    mp.enableScrollWheelZoom();        // 复杂的自定义覆盖物    $.get('/ph/Api/get_ban_map_point',function(res){        res = JSON.parse(res);        var aDate = res.data.point.length;        console.log(res);        for(var i=0;i<aDate;i++){                ComplexCustomOverlay.prototype = new BMap.Overlay();    ComplexCustomOverlay.prototype.initialize = function(map){      this._map = map;      var div = this._div = document.createElement("div");      div.style.backgroundColor = "#2d69f9";            div.style.color = "white";      div.style.width = "110px";      div.style.padding = "5px";      div.style.lineHeight = "18px";      div.style.whiteSpace = "nowrap";      div.style.MozUserSelect = "none";      div.style.fontSize = "12px"      var span = this._span = document.createElement("span");      div.appendChild(span);      span.appendChild(document.createTextNode(this._text));            var that = this;      var arrow = this._arrow = document.createElement("div");      arrow.style.width = "0px";      arrow.style.position = "absolute";      arrow.style.height = "0px";      arrow.style.borderLeft = "10px solid transparent";      arrow.style.borderRight = "10px solid transparent";      arrow.style.borderTop="10px solid #2d69f9"       arrow.style.left="20px";      arrow.style.top="25px";      div.appendChild(arrow);           div.onmouseover = function(){        this.style.backgroundColor = "#ff6400";        arrow.style.borderLeft = "10px solid transparent";        arrow.style.borderRight = "10px solid transparent";        arrow.style.borderTop="10px solid #ff6400" ;      }      div.onmouseout = function(){        this.style.backgroundColor = "#2d69f9";//      this.style.borderColor = "#BC3B3A";        this.getElementsByTagName("span")[0].innerHTML = that._text;//      arrow.style.backgroundPosition = "0px 0px";          arrow.style.borderLeft = "10px solid transparent";          arrow.style.borderRight = "10px solid transparent";          arrow.style.borderTop="10px solid #2d69f9" ;      }      mp.getPanes().labelPane.appendChild(div);            return div;    }    ComplexCustomOverlay.prototype.draw = function(){      var map = this._map;      var pixel = map.pointToOverlayPixel(this._point);//    this._div.style.left = pixel.x - parseInt(this._arrow.style.left) + "px";//    this._div.style.top  = pixel.y - 30 + "px";    }            var myCompOverlay = new ComplexCustomOverlay(new BMap.Point(res.data.point[i].BanGpsX,res.data.point[i].BanGpsY), res.data.point[i].BanID);    mp.addOverlay(myCompOverlay);           }    })//get        function ComplexCustomOverlay(point, text){      this._point = point;      this._text = "编号:"+text;      }为什么位置都凑到一起去了。