【百度地图API】你看过房产地图吗？你知道房产标注是如何建立的吗？

你是不是看过很多房产网站？例如安居客，新浪乐居。
你是不是也想做一个能写文字的标注？
你知道怎么去实现麼?



其实，上图这样的标注是一个“自定义覆盖物”。你可以任意指定它的样式，文字，图片等等。

首先，我需要初始化地图：

var mp = new BMap.Map("map_container");
var point = new BMap.Point(116.3964,39.9093);
mp.centerAndZoom(point,15);

然后，我建立两个自定义覆盖物：

var myCompOverlay = new ComplexCustomOverlay(new BMap.Point(116.407845,39.914101), "天安门东");
var myCompOverlay2 = new ComplexCustomOverlay(new BMap.Point(116.406946,39.911403), "国家博物馆");

对自定义覆盖物定义：（包括样式、图片、位置偏移等等）

// 复杂的自定义覆盖物
function ComplexCustomOverlay(point, text){
this._point = point;
this._text = text;
}
ComplexCustomOverlay.prototype = new BMap.Overlay();
ComplexCustomOverlay.prototype.initialize = function(map){
this._map = map;
var div = this._div = document.createElement("div");
div.style.position = "absolute";
div.style.zIndex = BMap.Overlay.getZIndex(this._point.lat);
div.style.backgroundColor = "#EE5D5B";
div.style.border = "1px solid #BC3B3A";
div.style.color = "white";
div.style.height = "18px";
div.style.padding = "2px";
div.style.lineHeight = "18px";
div.style.whiteSpace = "nowrap";
div.style.MozUserSelect = "none";
div.style.fontSize = "12px"
div.appendChild(document.createTextNode(this._text));

var arrow = this._arrow = document.createElement("div");
arrow.style.background = "url(http://map.baidu.com/fwmap/upload/r/map/fwmap/static/house/images/label.png) no-repeat";
arrow.style.position = "absolute";
arrow.style.width = "11px";
arrow.style.height = "10px";
arrow.style.top = "22px";
arrow.style.left = "10px";
arrow.style.overflow = "hidden";
div.appendChild(arrow);

div.onmouseover = function(){
this.style.backgroundColor = "#6BADCA";
this.style.borderColor = "#0000ff";
arrow.style.backgroundPosition = "0px -20px";
}

div.onmouseout = function(){
this.style.backgroundColor = "#EE5D5B";
this.style.borderColor = "#BC3B3A";
arrow.style.backgroundPosition = "0px 0px";
}

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";
}

最后，在地图上把它们添加上来。

mp.addOverlay(myCompOverlay);
mp.addOverlay(myCompOverlay2);

运行示例，请点击：
http://ui-love.com/baidumap/customoverlay.html