/// <summary>
        /// 删除图层
        /// </summary>
        /// <param name="map"></param>
        /// <param name="tree"></param>
        /// <param name="cmd"></param>
        private void DeleteLayer(MapImage map, MyTree tree, string[] cmd)
        {
            if (cmd.Length != 3)
            {
                return;
            }
            decimal  layerid   = GetId(cmd[2]);
            TreeNode layernode = FindLayer(tree.Nodes[0], layerid);

            if (layernode == null)
            {
                return;
            }
            //取得当前图层
            VectorLayer layer = layernode.Tag as VectorLayer;

            if (map.NeedSave && layer.NeedSave)
            {
                MapDBClass.DeleteLayer(map.Map.MapId, layer.ID);
            }
            //删除选择的图层
            map.Map.Layers.Remove(layer);
            TreeNode parentnode = layernode.Parent;

            //删除选择的节点
            tree.Nodes.Remove(layernode);
            if (parentnode.Nodes.Count <= 0)
            {
                parentnode.Remove();
            }
            foreach (TreeNode node in tree.Nodes[0].Nodes)
            {
                if (node.Nodes.Count <= 0)
                {
                    node.Remove();
                }
            }
        }