Question

    operation = (sender as AnyObject).tag

我正在使用计算器应用程序，而在底部，我尝试将操作发送到sender.tag，但出现错误

无法分配类型为“ Int！”的值键入“字符串”

This error also generates more errors in the bottom like

“替代”只能在类成员上指定”

“'super'不能在班级成员之外使用”

“'override'只能在类成员上指定”

“'super'不能在班级成员之外使用”

这些行会产生错误吗？

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

Answer 1

错误非常明显。您的operation变量是String。您正在尝试为其分配一个不兼容的类型Int。

let number = (sender as AnyObject).tag
operation = String(number)

OR

operation = "\(number)"

您的课堂应该看起来像这样。

class YourClass: UIViewController {
    // ...

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

无法分配类型为“ Int！”的值键入“字符串”

1 个答案: