关于调用百度地图api行政区域白色遮罩问题

<script type="text/javascript">
    // 百度地图API功能
    var map = new BMap.Map("allmap");
    map.centerAndZoom(new BMap.Point(116.403765, 39.914850), 5);
    map.enableScrollWheelZoom();

    function getBoundary(){       
        var bdary = new BMap.Boundary();
        bdary.get("北京市海淀区", function(rs){       //获取行政区域
            map.clearOverlays();        //清除地图覆盖物       
            var count = rs.boundaries.length; //行政区域的点有多少个
            if (count === 0) {
                alert(‘未能获取当前输入行政区域‘);
                return ;
            }
              var pointArray = [];
            for (var i = 0; i < count; i++) {
                var ply = new BMap.Polygon(rs.boundaries[i], {strokeWeight: 2, strokeColor: "#ff0000"}); //建立多边形覆盖物
                map.addOverlay(ply);  //添加覆盖物
                pointArray = pointArray.concat(ply.getPath());
            }    
            map.setViewport(pointArray);    //调整视野  
            addlabel();               
        });   
    }

    setTimeout(function(){
        getBoundary();
    }, 2000);

</script>

function getBoundary(){       
        var bdary = new BMap.Boundary();
        bdary.get("贵州省", function(rs){       //获取行政区域
            map.clearOverlays();        //清除地图覆盖物       
            var count = rs.boundaries.length; //行政区域的点有多少个
            if (count === 0) {
                alert(‘未能获取当前输入行政区域‘);
                return ;
            }
              var pointArray = [];
            for (var i = 0; i < count; i++) {
                var ply = new BMap.Polygon(rs.boundaries[i], {strokeWeight: 2, strokeColor: "#ff0000",fillColor:""}); //建立多边形覆盖物
                map.addOverlay(ply);  //添加覆盖物
                pointArray = pointArray.concat(ply.getPath());
            }    
            map.setViewport(pointArray);    //调整视野  
            addlabel();               
        });   
    }