执行循环后的performSegue

问题描述

我有一个带有联系人列表的帐户对象，我想要做的是在该postContact之后对嵌套的postAccount进行网络调用。 sideNotes：我们没有批量插入端点，因为我正在使用for循环逐个进入联系人，在循环完成后，有人可以帮助我嵌套调用性能performSegue吗？

 func showUIAlertCreate(_ numberOfNewUsers:Int) {
        let alert = UIAlertController(title: "Company Created",message: "A new Account has been created and \(numberOfNewUsers) new users have been added.",preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "OK",style: .default,handler: { action in
            
            DataService.shared.PostAccount("v2","26abd11fb",UUID().uuidString,self.txtfCompanyName.text!,self.dataSource.newContacts,self.stakeholderID,completion: {  result in
                
                switch result {
                    case .success(let account):
                        dispatchQueue.main.async{
                            for contact in self.dataSource.newContacts{
                                DataService.shared.PostContacts("v2",account.accountID,contact,completion: {result in
                                    
                                    switch result {
                                        case .success(let result):
                                            break;
                                        case .failure(let error):
                                            fatalError("message: error \(error)")
                                        break;
                                    }
                                })
                                self.performSegue(withIdentifier: "seguetoUsersTab",sender: nil)
                            }
                        }
                        break;
                    case .failure(let error):
                        fatalError("message: error \(error)")
                }
            })
        }))
        self.present(alert,animated: true,completion: nil)
    }

解决方法

如果要在完成for循环中的所有操作后执行segue，则必须将Perform segue行移到更像这样的地方。

DispatchQueue.main.async{
    for contact in self.dataSource.newContacts{
        DataService.shared.PostContacts("v2","26abd11fb",account.accountID,contact,completion: {result in
            
            switch result {
                case .success(let result):
                    break;
                case .failure(let error):
                    fatalError("message: error \(error)")
                break;
            }
        })
        // old line here 
    }
    // this will only execute AFTER FOR LOOP 
    self.performSegue(withIdentifier: "segueToUsersTab",sender: nil)
}