DispatchGroup AB执行完了执行C

 let group = DispatchGroup()

//A
        group.enter()
        DispatchQueue.global().async {
            
           
          NetWorkTools.shareInstance.getInviteUrl(completion: { (dict, error) in
                group.leave()
                 //........

            })
        }


//B
group.enter()
        DispatchQueue.global().async {
            
           
          NetWorkTools.shareInstance.getInviteUrl(completion: { (dict, error) in
                group.leave()
                 //........

            })
        }

//C
group.notify(queue: DispatchQueue.main, execute: {
            
            print("操作完成")
            
        })