问题描述
我有来自不同位置的警报，所以我决定调用一个函数。
I have alert that is being fired from different location so I decided to make a function to be called.
func alertSCFlag(x: Int) {
var alert = UIAlertController()
switch x {
case 1:
alert = UIAlertController(title: "Not Finished", message: "sorry but you must give the project a title and description", preferredStyle: UIAlertControllerStyle.alert)
default:
alert = UIAlertController(title: "Not Finished", message: "sorry but you need to choose a type of project", preferredStyle: UIAlertControllerStyle.alert)
}
alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
问题是，自我显然不是普遍的，我无法弄清楚如何通过它。有没有办法通过自我或更好的方式来解决整体问题？
The problem is that the self obviously isn't universal and I'm having trouble figuring out how to pass it. Is there a way to pass self or better yet a superior way to approach the problem overall?
推荐答案
你需要的是扩展UIViewController这种方式你不需要传递任何视图控制器作为参数，而self将始终是一个视图控制器。并确保调用视图控制器的当前方法 present（_ viewControllerToPresent：UIViewController，动画标志：Bool，完成：（（） - > Void）？= nil）来自主线程：
What you need is to extend UIViewController this way you don't need to pass any view controller as parameter and self will always be a view controller. And make sure you call the view controller's present method present(_ viewControllerToPresent: UIViewController, animated flag: Bool, completion: (() -> Void)? = nil) from the main thread:
extension UIViewController {
enum Message: CustomStringConvertible {
case missingTitle, chooseProject
var description: String {
let message: String
switch self {
case .missingTitle: message = "sorry but you must give the project a title and description"
case .chooseProject: message = "sorry but you need to choose a type of project"
}
return message
}
}
func alertSCFlag(title: String = "Not Finished", message: Message) {
let alert = UIAlertController(title: title, message: message.description, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Ok", style: .default))
DispatchQueue.main.async {
self.present(alert, animated: true)
}
}
}
用法：
Usage:
let vc = UIViewController()
vc.alertSCFlag(message: .chooseProject)
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