如何在 Swift 中创建一个 UIAlertView？

Question

I have been working to create a UIAlertView in Swift, but for some reason I can't get the statement right because I'm getting this error:

Could not find an overload for 'init' that accepts the supplied arguments

Here is how I have it written:

let button2Alert: UIAlertView = UIAlertView(title: "Title", message: "message",
                     delegate: self, cancelButtonTitle: "OK", otherButtonTitles: nil)

Then to call it I'm using:

button2Alert.show()

As of right now it is crashing and I just can't seem to get the syntax right.

转载于:https://stackoverflow.com/questions/24022479/how-would-i-create-a-uialertview-in-swift

Answer 1

From the UIAlertView class:

// UIAlertView is deprecated. Use UIAlertController with a preferredStyle of UIAlertControllerStyleAlert instead

On iOS 8, you can do this:

let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.Default, handler: nil))
self.presentViewController(alert, animated: true, completion: nil)

Now UIAlertController is a single class for creating and interacting with what we knew as UIAlertViews and UIActionSheets on iOS 8.

Edit: To handle actions:

alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { action in
    switch action.style{
    case .Default:
        print("default")

    case .Cancel:
        print("cancel")

    case .Destructive:
        print("destructive")
    }
}}))

Edit for Swift 3:

let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)

Edit for Swift 4:

let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { action in
      switch action.style{
      case .default:
            print("default")

      case .cancel:
            print("cancel")

      case .destructive:
            print("destructive")


}}))
self.present(alert, animated: true, completion: nil)