uialertview - 快速显示 UIAlertView 时出错

Question

我试图在我的 swift 应用程序中显示一个 UIAlertView

    alert = UIAlertView(title: "",
        message: "bla",
        delegate: self,
        cancelButtonTitle: "OK")
    alert!.show()

=> BAD_ACESS 错误: -[_UIAlertViewAlertControllerShim initWithTitle:message:delegate:cancelButtonTitle:otherButtonTitles:] ()

所以我怀疑自己。我把它设置为零

    alert = UIAlertView(title: "",
        message: "bla",
        delegate: nil,
        cancelButtonTitle: "OK")
    alert!.show()

=> ARM_DA_ALIGN 错误: -[_UIAlertViewAlertControllerShim initWithTitle:message:delegate:cancelButtonTitle:otherButtonTitles:] ()

---

完整代码

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, UIAlertViewDelegate {

    @lazy var window = UIWindow(frame: UIScreen.mainScreen().bounds)
    @lazy var locationManager = CLLocationManager()
    var alert: UIAlertView? = nil

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: NSDictionary?) -> Bool {
        //setup dummy window
        self.window.backgroundColor = UIColor.whiteColor()
        self.window.rootViewController = UIViewController()
        self.window.makeKeyAndVisible()

        alert = UIAlertView(title: "",
            message: "bla",
            delegate: nil,
            cancelButtonTitle: "OK")
        alert!.show()

    return true
    }
}

怎样做才是对的？ :)

Answer 1

swift 5

你应该这样做:

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