ViewController 关闭 swift ios

Posted 2023-03-11

【中文标题】ViewController 关闭 swift ios

【英文标题】：ViewController dismiss swift ios

【发布时间】：2017-03-24 18:56:52

【问题描述】：

您好，我的英语不是很好，我提前道歉。

我的申请有问题。场景如下我将我的 rootViewController 分配给我的 ViewController 控制器，这是我的开始。我还有其他屏幕是描述屏幕，其中有两个登录和注册按钮，预加载时会将我带到他们的控制器。

现在，当我在日志全屏表单上并发送解雇命令时：

ViewController 注册

self.dismiss(animated: false, completion: nil)

一切正常，视图被隐藏，但是当进入前一个屏幕时，如果有解除命令，我会验证是否已经有用户：

ViewController 描述应用

self.dismiss(animated: false, completion: nil)

但它不执行操作。

代码

UIViewController

class ViewController: UIViewController 

    override func viewDidLoad() 

        FIRAuth.auth()!.addStateDidChangeListener()  auth, user in
            if user == nil 
                let descriptionController = DescriptionController()
                present(descriptionController, animated: true, completion: nil)
            

        
    

描述控制器

class DescriptionController: UIViewController 

    @IBOutlet weak var sign_in_custom: UIButton!

    override func viewDidLoad() 

        FIRAuth.auth()!.addStateDidChangeListener()  auth, user in
            if user != nil 
               self.dismiss(animated: false, completion: nil)
            

        

        sign_in_custom.addTarget(self, action: #selector(changeToSingIn), for: [.touchUpInside])
    

    func changeToSingIn() 
        let singInController = SingInController()
        present(singInController, animated: true, completion: nil)
    

SingInController

class SingInController: UIViewController 
    @IBOutlet weak var sign_in_custom: UIButton!
    override func viewDidLoad() 
        sign_in_custom.addTarget(self, action: #selector(singIn), for: [.touchUpInside])
    
    func showLoad() 
        let alert = UIAlertController(title: nil, message: "Please wait...", preferredStyle: .alert)
        alert.view.tintColor = UIColor.black
        let loadingIndicator: UIActivityIndicatorView = UIActivityIndicatorView(frame: CGRectMake(10, 5, 50, 50) ) as UIActivityIndicatorView
        loadingIndicator.hidesWhenStopped = true
        loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
        loadingIndicator.startAnimating();
        alert.view.addSubview(loadingIndicator)
        present(alert, animated: true, completion: nil)
    
    func hideLoad() 
        self.dismiss(animated: false, completion: nil)
    
    func singIn() 
        if (emailVarification())
            if (passwordVarification())
                showLoad()
                guard let email = emailTextField.text else  return 
                guard let password = passwordTextField.text else  return 
                FIRAuth.auth()?.createUser(withEmail: email, password: password)  (user, error) in
                    hideLoad()
                    if (user != nil) 
                        self.dismiss(animated: false, completion: nil)
                     else 
                        let alert = UIAlertController(title: "Error", message: "This is a error", preferredStyle: UIAlertControllerStyle.alert)
                        alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: nil))
                        self.present(alert, animated: true, completion: nil)
                    
                
             else 
                let alert = UIAlertController(title: "Error", message: "This is a error", preferredStyle: UIAlertControllerStyle.alert)
                alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: nil))
                self.present(alert, animated: true, completion: nil)
            
         else 
            let alert = UIAlertController(title: "Error", message: "This is a error", preferredStyle: UIAlertControllerStyle.alert)
            alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: nil))
            self.present(alert, animated: true, completion: nil)
        
    

sequence

【参考方案1】：

这是因为第二个控制器基本上只是放在现有控制器的顶部。第一个视图仍在第二个视图下运行，当第二个视图关闭时，第一个视图不会调用 ViewDidLoad。因此，要解决它，您可能希望将其添加到 ViewDidAppear 函数中。

【参考方案2】：

在ViewdidAppear中使用此代码：

FIRAuth.auth()!.addStateDidChangeListener()  auth, user in
        if user != nil 
           self.dismiss(animated: false, completion: nil)
        

    

    sign_in_custom.addTarget(self, action: #selector(changeToSingIn), for: [.touchUpInside])

【参考方案3】：

与其让 DescriptionController 自行关闭，更好的方法是通知 ViewController 用户已登录，并在必要时返回任何错误。然后 ViewController 可以根据登录成功或失败执行所需的任何其他步骤。这可以通过使用委托模式来完成（DescriptionController 定义了一个协议，而 ViewController 实现了它）。