参考资料

[](https://www.cnblogs.com/sethnie/p/15856122.html)

[GMap.Net 在 winform 中开发 绘制多边形和轨迹](https://www.cnblogs.com/sethnie/p/15856131.html)

绘制多边形并着色

            // 添加多边形节点
            List points = new List();
            points.Add(new PointLatLng(37.1412768409666, 79.6562057733536));
            points.Add(new PointLatLng(37.1403574434934, 79.6564793586731));
            points.Add(new PointLatLng(37.1405669815751, 79.6581155061722));
            points.Add(new PointLatLng(37.1416146632773, 79.6577936410904));
            points.Add(new PointLatLng(37.1412768409666, 79.6562057733536));

            //绘制多边形用GMapPolygon 
            GMapPolygon polygon = new GMapPolygon(points, "polygons");
            polygon.Fill = new SolidBrush(Color.FromArgb(50, Color.Green));// 配置多边形填充颜色
            polygon.Stroke = new Pen(Color.Red, 1);
            polyOverlay.Polygons.Add(polygon);
            gMapControl.Overlays.Add(polyOverlay);

改变着色

/// 

        /// 改变 Polygons 填充颜色
        /// 
        /// Polygons 名称
        /// Polygons 填充颜色
        void changePolygonsColor(String name,Color color)
        {
            for (int i = 0; i < gMapControl.Overlays.Count; i++)
            {
                for (int j = 0; j < gMapControl.Overlays[i].Polygons.Count; j++)
                {
                    if (gMapControl.Overlays[i].Polygons[j].Name == name)
                    {
                        gMapControl.Overlays[i].Polygons[j].Fill = new SolidBrush(Color.FromArgb(50, color));
                    }
                }
            }
        }