如何弹出视图控制器并显示UIAlertController
如何弹出视图控制器并显示UIAlertController
提问于 2018-07-27 03:28:17
假设ViewController2中有一个错误，我想返回到上一个视图控制器ViewController1，然后显示一个警告。现在如果我把这个放到ViewController2中
@IBAction func testing(_ sender: Any) {
navigationController?.popViewController(animated: true)
Alert.alert(userTitle: "Error", userMessage: " ", userOptions: " ", in: LandingViewController() as UIViewController)
}将其用作Alert类
public class Alert {
class func alert(userTitle: String?, userMessage: String, userOptions: String, in vc: UIViewController) {
DispatchQueue.main.async {
let alert = UIAlertController(title: userTitle, message: userMessage, preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: userOptions, style: UIAlertActionStyle.default, handler: nil))
vc.present(alert, animated: true, completion: nil)
}
}
}它将抛出一个错误
那么有没有办法做到这一点呢？
回答 1
Stack Overflow用户
回答已采纳
发布于 2018-07-27 03:39:42
问题是LandingViewController() as UIViewController不是在UiWindow中呈现的
尝尝这个
guard let nav = navigationController, let top = nav.topViewController else {
return
}
nav.popViewController(animated: true)
Alert.alert(userTitle: "Error", userMessage: " ", userOptions: " ", in: top)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/51546237
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