调用函数将 UIViewController 推入闭包内，就好像它在外面一样

Posted 2023-03-13

【中文标题】调用函数将 UIViewController 推入闭包内，就好像它在外面一样

【英文标题】：Call function pushing UIViewController inside closure as though it were outside

【发布时间】：2017-07-26 07:03:02

【问题描述】：

我在另外两个闭包（entireDescView.customize（第二个闭包）和description（第一个闭包））中有一个闭包（handleMentionTap）。现在我想调用位于同一个类中的函数pushProfileController(of: String)（为了推送另一个视图控制器（newController）。这些函数需要在闭包内部调用，因为在外部调用它们会导致内存泄漏我目前不知道的一个原因（我正在使用一个名为ActiveLabel 的库，不是我自己编写的）。但是，newController 没有被推送（即使我使用了DispatchQueue.main.async，正如关于*** 的一些答案中所建议的那样类似的问题). 不过newController 似乎已创建及其数据集(我正在使用var passedData: String? didSet print(passedData) 打印数据). 我怎样才能推动控制器就像它在关闭之外(例如使用self.pushProfileController(of: username)？我会非常感谢您的帮助！

swift（同一个类）：

var pushingViewController = false

//...

func pushProfileController(of: String) 
    if self.pushingViewController == false 
        self.pushingViewController = true
        DispatchQueue.main.async 
            let newController = NewController()
            newController.passedData = of //passedData is a string
            self.navigationController?.pushViewController(newController, animated: true)
        

        self.pushingViewController = false
    


let description: ActiveLabel = 

    let entireDescView = ActiveLabel()

    //set properties of controls container view

    //recognize (@hotel_x) and be able to push controller of 'hotel_x'
    entireDescView.customize( (entireDescView) in
        entireDescView.enabledTypes = [.mention]
        entireDescView.mentionColor = UIColor(red: 25/255, green: 153/255, blue: 1, alpha: 1)
        entireDescView.handleMentionTap  username in
            self.pushProfileController(of: username) //also tried ThisClass().pushProfileController(of: username) which didn't push the controller either
        
    )

    return entireDescView

()

【参考方案1】：

你检查过navigationController? 存在吗？

在尝试推送 viewController 之前尝试添加以下内容：

func pushProfileController(of: String) 
    if self.pushingViewController == false 
        self.pushingViewController = true
        DispatchQueue.main.async 
            guard let navController = self.navigationController else  return print("navigationController was nil") 
            let newController = NewController()
            newController.passedData = of //passedData is a string
            navController.pushViewController(newController, animated: true)
        

        self.pushingViewController = false