Question

我想创建一个结构类型参数，这样我只能传递两个值作为参数，但我不想使用Bool.Kindly帮我处理下面的代码，或者请详细说明我做错了什么。刚开始编码。

struct Alert {
    let alert = "Alert"
    let info  = "Information"
} 

func information(message : String) {
    AskConfirmation(type : Alert.info , title: "Information", message: message, completion: { (bool) in
        self.dismiss(animated: true, completion: nil)
    })
}

func alert(message : String) {
    AskConfirmation(type : Alert.alert , title: "Alert", message: message, completion: { (bool) in
        self.dismiss(animated: true, completion: nil)
    })
}

func askConfirmation (type : Alert.Type, title : String, message : String, completion:@escaping (_ result:Bool) -> Void) {
    if type == Alert.alert {
        let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
        self.present(alert, animated: true, completion: nil)

        alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { action in
            completion(true)
        }))

        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { action    in
            completion(false)
        }))
    }else if type == Alert.info {
        let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
        self.present(alert, animated: true, completion: nil)
        alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { action in
            completion(true)
        }))
    }
}

我将使用自定义警报功能。

alert(message: "Priority not selected")
askConfirmation(type : "Information" , title: "Information", message: "Quote saved successfully", completion: nil)

Answer 1

改为使用enumeration：

enum Alert {
    case alert
    case info
}

func information(message : String) {
    AskConfirmation(type : Alert.info , title: "Information", message: message, completion: { (bool) in
        self.dismiss(animated: true, completion: nil)
    })
}

func alert(message : String) {
    AskConfirmation(type : Alert.alert , title: "Alert", message: message, completion: { (bool) in
        self.dismiss(animated: true, completion: nil)
    })
}

func askConfirmation (type : Alert, title : String, message : String, completion:@escaping (_ result:Bool) -> Void) {
    if type == Alert.alert {
        let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
        self.present(alert, animated: true, completion: nil)

        alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { action in
            completion(true)
        }))

        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { action    in
            completion(false)
        }))
    }else if type == Alert.info {
        let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
        self.present(alert, animated: true, completion: nil)
        alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { action in
            completion(true)
        }))
    }
}

在您的情况下，您希望有两个预定义的自定义值（因此不是布尔值），枚举使您能够做到这一点。

我建议您使用枚举来查看这些advanced techniques。

Answer 2

您的代码无法正常工作的原因是您正在直接访问尚未设置的值。

df[df.astype(str).KEY.str[1:3] == '02']
Out[34]: 
       KEY
1  1024876

将值更改为静态可让您直接访问它们。

我如何或可以在函数的参数中传递结构？

2 个答案: