ios - 开启 UIButton title : Expression pattern of type 'String' cannot match values of type 'String?!'

Question

我正在尝试在 @IBAction 方法中使用一个开关，该方法连接到多个按钮

@IBAction func buttonClick(sender: AnyObject) {

        switch sender.currentTitle {
            case "Button1":
                print("Clicked Button1")
            case "Button2":
                print("Clicked Button2")
            default:
                break
        }

当我尝试上述操作时，出现以下错误:

Expression pattern of type 'String' cannot match values of type 'String?!'

Answer 1

currentTitle 是可选的，因此您需要将其解包。此外，sender 的类型应该是 UIButton，因为您正在访问 currentTitle 属性。

@IBAction func buttonClick(sender: UIButton) {
    if let theTitle = sender.currentTitle {
        switch theTitle {
            case "Button1":
                print("Clicked Button1")
            case "Button2":
                print("Clicked Button2")
            default:
                break
        }
    }
}