您好，对于面几何对象构造岛洞对象使用拓扑字段就可以实现，
partTopo表示的是part的拓扑结构，1代表岛，-1代表洞；所对应的part即相应的子对象所包含的节点个数。比如以下这个就是有岛洞的对象
{"stringID":null,"fieldNames":["SMID","SMUSERID","SMAREA","SMPERIMETER","SMGEOPARAM"],"geometry":{"center":{"x":297.19245057784997,"y":238.7785332671},"parts":[5,5],"style":null,"prjCoordSys":null,"id":1,"type":"REGION","partTopo":[1,-1],"points":[{"x":269.7049234104,"y":257.991956743},{"x":314.8942589563,"y":257.991956743},{"x":314.8942589563,"y":223.3839268796},{"x":269.7049234104,"y":223.3839268796},{"x":269.7049234104,"y":257.991956743},{"x":279.4906421994,"y":249.7974117409},{"x":304.55162934189997,"y":249.7974117409},{"x":304.55162934189997,"y":227.7596547933},{"x":279.4906421994,"y":227.7596547933},{"x":279.4906421994,"y":249.7974117409}]},"fieldValues":["1","0","1011.625930566367","253.79221899879997",""],"ID":1}
希望可以帮助到您。
