在Swift中显示警报视图会导致EXC BAD ACCESS

Question

我有以下视图控制器。它只是从文本字段中读取要在UIAlertView中显示的值。

import UIKit

class ViewController: UIViewController {

    @IBOutlet var textField: UITextField!

    @IBAction func pressButton(sender: UIButton) {
        let name = textField.text

        let alert = UIAlertView(
            title: "Hello!",
            message: "How are you today, \(name). I'm lovely!",
            delegate: nil,
            cancelButtonTitle: "Thanks!"
        )

        alert.show() // EXC_BAD_ACCESS
    }
}

为什么alert.show()与EXC_BAD_ACCESS崩溃？我的UIAlertView实例发生了什么？为什么它不像我认为的那样在alert？

Answer 1

尝试使用var代替lat，如下所示

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