导航到另一个 xib 时未在 AppKit（主）线程问题上运行

Posted 2023-02-26

【中文标题】导航到另一个 xib 时未在 AppKit（主）线程问题上运行

【英文标题】：not running on AppKit (main) thread issue when navigating to another xib

【发布时间】：2018-09-05 09:42:36

【问题描述】：

我的应用程序的用例是有一个在SafariExtensionViewController.xib 中处理的登录用户界面，当用户点击登录按钮时，必须显示另一个用户界面，即ExtensionStepsViewController.xib。我使用以下导航到另一个屏幕

self.presentViewControllerAsSheet(ExtensionStepsViewController())

但是，我遇到了以下问题

void assertRunningOnAppKitThread(void)() 中的断言失败，2018-09-05 15:02:30.318742+0545 扩展 [13150:1422110] [General] 不在 AppKit（主）线程上运行

这是我的代码

SafariExtensionViewController.swift

import SafariServices

class SafariExtensionViewController: SFSafariExtensionViewController 


    @IBOutlet weak var passwordMessage: NSTextField!
    @IBOutlet weak var emailMessage: NSTextField!
    @IBOutlet weak var message: NSTextField!
    @IBOutlet weak var email: NSTextField!
    @IBOutlet weak var password: NSSecureTextField!
    static let shared = SafariExtensionViewController()
    override func viewDidLoad() 
        message.stringValue = ""
        emailMessage.stringValue = ""
        passwordMessage.stringValue = ""
    


    @IBAction func userLogin(_ sender: Any) 
        let providedEmailAddress = email.stringValue
        let providedPassword = password.stringValue
        let isEmailAddressValid = isValidEmailAddress(emailAddressString: providedEmailAddress)
        self.message.stringValue = ""
        emailMessage.stringValue = ""
        passwordMessage.stringValue = ""
        if isEmailAddressValid && providedPassword.count > 0 
            let session = URLSession.shared
            var request = URLRequest(url: URI!)
            request.httpMethod = "POST"
            do 
                request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
             catch let error 
                print(error.localizedDescription)
            
            request.addValue("application/json", forHTTPHeaderField: "Content-Type")
            let task = session.dataTask(with: request as URLRequest, completionHandler:  data, response, error in

                guard error == nil else 
                    return
                

                guard let data = data else 
                    return
                

                do 
                    //create json object from data
                    if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] 
                        if let httpResponse = response as? HTTPURLResponse 
                            if (httpResponse.statusCode >= 200 && httpResponse.statusCode < 300) 
                                print("#########LOGIN########################")
                                self.message.stringValue = "Login Successful"
                                self.message.textColor = NSColor.green

                                UserDefaults.standard.set(providedEmailAddress, forKey: "email")
                                self.presentViewControllerAsSheet(ExtensionStepsViewController()) // error is thrown after this action
                             else 
                                self.message.stringValue = "Invalid Credentials"
                                self.message.textColor = NSColor.red
                            
                        
                        // handle json...
                    
                 catch let error 
                    print(error.localizedDescription)
                
            )
            task.resume()
         else 
            emailMessage.textColor = NSColor.red
            emailMessage.stringValue = "Invalid Email"
        
    

  

ExtensionStepsViewController.swift

import SafariServices

class ExtensionStepsViewController: SFSafariExtensionViewController 

//    static let shared = SafariExtensionViewController()
    override func viewDidLoad() 
        super.viewDidLoad()
        print("Hello") // this is also printed 
        // Do view setup here.
    

当登录成功，然后这个语句被执行self.presentViewControllerAsSheet(ExtensionStepsViewController())print("hello") 被打印在调试部分，我得到了列出的问题。

【参考方案1】：

UI 的所有更新都必须在主线程中完成。好像主线程没有调用completionHandler，导致这个断言失败。

您需要在主队列中进行演示。您可以通过如下安排一个块来做到这一点：

DispatchQueue.main.async 
  // This will  now run on the main queue.
  self.presentViewControllerAsSheet(ExtensionStepsViewController())

【讨论】：

我不知道这个是否有效，但问题现在不存在。它可以导航，但窗口会在一秒钟内关闭。

那是因为没有人持有对该对象的强引用——它正在被释放