在地图上增加标注点并为每个点增加各自的信息窗口

 //请求用户微博信息
 function request(user_id){
     createXMLHttpRequest();
     xmlHttp.onreadystatechange = back;
     var str = getUrl();
     var url = str + "/points_handle.php?uid=" + user_id;
     xmlHttp.open("GET",url,true);
     xmlHttp.send(null);      
 } 
 //得到微博信息
 function back() {
     if(xmlHttp.readyState == 4){
         if(xmlHttp.status == 200) { //status状态正常时    
            
            var response = xmlHttp.responseText;
            var obj = eval('('+response+')');    //将json数据转换为对象(object)形式
            //alert(response);
            
            if( obj.data != null ){
                
                for(var i = 0; i < obj.data.length; i++)
                {
                    (function(x){
                        
                        //alert(obj.data[i].point[1]);
                        var pt = new BMap.Point(obj.data[i].point[1],obj.data[i].point[0]);
                        var marker = new BMap.Marker(pt);
                        
                        var text = obj.data[i].text;
                        var length = text.length;
                        //alert(text.length);
                        var opt = {
                            300,
                            height:length + 50,
                            title:'<span style="font-size:15px;color:red">' + obj.uid + '</span>'
                        }
                        
                        map.addOverlay(marker);    
                        marker.setAnimation(BMAP_ANIMATION_BOUNCE);
                        
                        marker.addEventListener("click",function(){
                            openInfo(text,marker,opt);
                        });        
                        
                    })(i);
                }    
                //map.addControl(new BMap.NavigationControl());
            }else{
                alert("数据库中没有该ID");
            }
            
         }
     }           
 } 
 function openInfo(text,marker,opt){
     var p = marker.getPosition();
     var point = new BMap.Point(p.lng,p.lat);
     var infoWindow = new BMap.InfoWindow(text,opt);
     map.openInfoWindow(infoWindow,point);
 }