SOURCE

//创建地图
var map = new BMap.Map("allmap");  
//创建一个多边形
 
//创建多边形  
var polygon2 = new BMap.Polygon([  
      new BMap.Point(112.579325,26.915291),  
      new BMap.Point(112.584967,26.899086),  
      new BMap.Point(112.608287,26.898023),  
      new BMap.Point(112.605035,26.90764),  
      new BMap.Point(112.602825,26.914356),  
      new BMap.Point(112.588254,26.909862),  
      ], {strokeColor:"#f50704",fillColor:"#cfcfcf", strokeWeight:5, strokeOpacity:0,fillOpacity:0,});  
 
 var point2s = [  
      new BMap.Point(112.586149,26.913201),  
      new BMap.Point(112.58464,26.909432),  
      new BMap.Point(112.585143,26.899219),  
      new BMap.Point(112.600953,26.898832),  
      new BMap.Point(112.607421,26.900572),  
      new BMap.Point(112.606631,26.904825),  
      new BMap.Point(112.606523,26.909142),  
      new BMap.Point(112.59772,26.909399),
      ];
//创建标注点并添加到地图中
function addMarker(points) {
    //循环建立标注点
    for(var i=0, pointsLen = points.length; i<pointsLen; i++) {
        var marker = new BMap.Marker(points[i]); //将点转化成标注点
        map.addOverlay(marker);  //将标注点添加到地图上
        //添加监听事件
        (function() {
            var thePoint = points[i];
            marker.addEventListener("click",
                function() {
                showInfo(this,thePoint);
            });
         })();  
    }
}
 
function showInfo(thisMarker,point) {
 
    //判断点是否在
    if(BMapLib.GeoUtils.isPointInPolygon(point,polygon2)){
      var infoWindow = new BMap.InfoWindow("在区域内");
      thisMarker.openInfoWindow(infoWindow); //图片加载完后重绘infoWindow
  }else
  {
     var infoWindow = new BMap.InfoWindow("不在区域内");
      thisMarker.openInfoWindow(infoWindow); //图片加载完后重绘infoWindow
  }
}
 
 
function initialize() {  
    alert("点击标注点可以显示是否在区域内");
  // 百度地图API功能  
  map.addControl(new BMap.NavigationControl());               // 添加平移缩放控件  
  map.addControl(new BMap.ScaleControl());                    // 添加比例尺控件  
  map.addControl(new BMap.OverviewMapControl());              //添加缩略地图控件  
  map.enableScrollWheelZoom();                            //启用滚轮放大缩小  
  map.addControl(new BMap.MapTypeControl());          //添加地图类型控件  
 
    var point = new BMap.Point(112.595384,26.904631);    // 创建点坐标  
        map.centerAndZoom(point,15);                      // 初始化地图,设置中心点坐标和地图级别。  
        addMarker(point2s); 
  map.addOverlay(polygon2);
}  
 
initialize();

<script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=U4hbhhgGEGAOQtb8N5AYIAWxYXOQMTi1"></script>



<div id="allmap"></div>