所以我最近开始将代码迁移到MVVM模式中,并且有一些问题。目前,我正在处理对用户进行身份验证的登录页。问题是我我调用我的功能,但是我的代码不等待它的响应,而是移至下一行。我认为这是因为Alamofire的异步内容。这是我的代码:
// My login view controller
class loginPageViewController: UIViewController, UITextFieldDelegate {
private var viewModel = userViewModel()
@IBOutlet weak var usernameTextField: UITextField!
@IBOutlet weak var passwordTextField: UITextField!
@IBAction func signInButton(_ sender: roundButton) {
if(usernameTextField.text != "" && passwordTextField.text != "") {
self.viewModel.validate(nameField: self.usernameTextField.text!, passField: self.passwordTextField.text!)
if(self.viewModel.isDone){
print("success")
self.presentPage(identifier: "homePageNavCtrl")
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
usernameTextField.delegate = self
passwordTextField.delegate = self
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool{
usernameTextField.resignFirstResponder()
passwordTextField.resignFirstResponder()
return true;
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
self.view.endEditing(true)
}
}
private extension loginPageViewController{
func displayErrorMessage(errorMessage: String){
let alert = UIAlertController(title: "Error", message: errorMessage, preferredStyle: UIAlertController.Style.alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
func presentPage(identifier: String){
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let nextViewController = storyBoard.instantiateViewController(withIdentifier: identifier)
self.present(nextViewController, animated:true, completion:nil)
}
}
我要做的是敲击登录按钮时,使用JSON请求验证用户,如果凭据正确,请移至下一页。
这是我的UserviewModel
class userViewModel{
private var mng = restInterface()
private var User = user()
var isDone = false
var id: Int {
return User.ID
}
var username: String {
return User.LOGINNAME
}
var password: String {
return User.PASSHASH
}
}
extension userViewModel{
func updateId(id: Int){
User.ID = id
}
func updateUsername(username: String){
User.LOGINNAME = username
}
func updatePassword(password: String){
User.PASSHASH = password
}
func validate(nameField: String, passField: String){
let accountBaseURL = "myUrlLiesDownHere"
var nm = nameField
var ps = passField
nm.insert("'", at: nm.startIndex)
nm.insert("'", at: nm.endIndex)
ps.insert("'", at: ps.startIndex)
ps.insert("'", at: ps.endIndex)
let params : [String: String] = ["sUser" : nm, "sPass" : ps, "sToken": "''"]
self.mng.performRequest(URLString: accountBaseURL, parameters: params, method: .get, successCallback: { (dict) in
self.User.ID = dict.value(forKey: "ID") as! Int
self.User.LOGINNAME = dict.value(forKey: "LOGINNAME") as! String
self.User.PASSHASH = dict.value(forKey: "PASSHASH") as! String
self.loginDone()
}) { (error) in
print("Error")
}
}
func loginDone(){
self.isDone = true
}
}
这是我的休息接口
class restInterface {
func performRequest(URLString: String, parameters : Parameters, method:HTTPMethod, successCallback: @escaping (NSDictionary) -> Void, errorCallBack: @escaping (String) -> Void) -> Void{
Alamofire.request(URLString, method: method, parameters: parameters).responseJSON { response in
print(response)
if let JSON = response.result.value as? [String: Any] {
print(JSON)
successCallback(JSON as NSDictionary)
} else {
errorCallBack("JSON Doesn't Exist")
}
}
}
}
当我在视图控制器中控制它时,UserviewModel上的ISDONE布尔值必须为真。但事实并非如此。当我按一下按钮一次时,结果将变为真,但什么也不会发生。当我再次击中它时,它将我重定向到我想要的下一页。因此,与async一起工作真的使我感到困惑,我在这里挖掘帮助:)谢谢...
在您的UserViewModel
中,创建一个completionHandler
回调并在viewController
内实现以显示下一个viewController
。
class UserViewModel {
public var loginCompletion: (()-> Void)?
private var mng = restInterface()
private var User = user()
// rest of your code
}
如果完成请求后,请致电completionHandler
,
extension userViewModel{
func validate(nameField: String, passField: String){
let accountBaseURL = "myUrlLiesDownHere"
var nm = nameField
var ps = passField
nm.insert("'", at: nm.startIndex)
nm.insert("'", at: nm.endIndex)
ps.insert("'", at: ps.startIndex)
ps.insert("'", at: ps.endIndex)
let params : [String: String] = ["sUser" : nm, "sPass" : ps, "sToken": "''"]
self.mng.performRequest(URLString: accountBaseURL, parameters: params, method: .get, successCallback: { (dict) in
self.User.ID = dict.value(forKey: "ID") as! Int
self.User.LOGINNAME = dict.value(forKey: "LOGINNAME") as! String
self.User.PASSHASH = dict.value(forKey: "PASSHASH") as! String
self.loginDone()
self.loginCompletion?()
}) { (error) in
print("Error")
}
}
func loginDone(){
self.isDone = true
}
}
completionHandler
viewController
中的用法,
class loginPageViewController: UIViewController, UITextFieldDelegate {
private var viewModel = userViewModel()
@IBOutlet weak var usernameTextField: UITextField!
@IBOutlet weak var passwordTextField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
usernameTextField.delegate = self
passwordTextField.delegate = self
self.viewModel.loginCompletion = { [weak self] in
print("success")
self?.presentPage(identifier: "homePageNavCtrl")
}
}
@IBAction func signInButton(_ sender: roundButton) {
if(usernameTextField.text != "" && passwordTextField.text != "") {
self.viewModel.validate(nameField: self.usernameTextField.text!, passField: self.passwordTextField.text!)
}
}
// rest of your code
}
注意:在Swift中,class/struct/enum
名称应以 Capital 字母开头。以上解决方案是一个非常基本的设置,用于观察视图模型之间的数据。您应该寻找一个更好的数据绑定解决方案,例如Rx-Swift,Bond,双向绑定等。
-----变更验证方法 -
func validate(nameField: String, passField: String, completionHandler: @escaping (_: NSDictionary?, _: NSError?) -> Void){
let accountBaseURL = "myUrlLiesDownHere"
var nm = nameField
var ps = passField
nm.insert("'", at: nm.startIndex)
nm.insert("'", at: nm.endIndex)
ps.insert("'", at: ps.startIndex)
ps.insert("'", at: ps.endIndex)
let params : [String: String] = ["sUser" : nm, "sPass" : ps, "sToken": "''"]
self.mng.performRequest(URLString: accountBaseURL, parameters: params, method: .get, successCallback: { (dict) in
self.User.ID = dict.value(forKey: "ID") as! Int
self.User.LOGINNAME = dict.value(forKey: "LOGINNAME") as! String
self.User.PASSHASH = dict.value(forKey: "PASSHASH") as! String
completionHandler(dict, nil)
}) { (error) in
print("Error")
completionHandler(nil, error)
}
}
-------调用该方法的调用 -
@IBAction func signInButton(_ sender: roundButton) {
if(usernameTextField.text != "" && passwordTextField.text != "") {
self.viewModel.validate(nameField: self.usernameTextField.text!, passField: self.passwordTextField.text!) { (resultDict, error) in
if error != nil {
print("Error")
} else {
print("success")
self.presentPage(identifier: "homePageNavCtrl")
}
}
}