将枚举类型作为通用参数传递给swift 2.2 iOS中的函数

I'm new to Swift iOS.. I'm trying to use enum type as input parameter to a function.. here is the

我是Swift iOS的新手。我正在尝试使用枚举类型作为函数的输入参数..这里是

sample enum type:

样本枚举类型:

public enum CFScreen {

public enum CFScreen_Newsfeed: Int {

    case Newsfeed_01 = 2100
    case Newsfeed_02 = 2101
    case Newsfeed_03 = 2102
    case Newsfeed_04 = 2103
    case Newsfeed_05 = 2104
    case Newsfeed_06 = 2105
    case Newsfeed_07 = 2106
    case Newsfeed_08 = 2107
}

public enum CFScreen_Groups: Int {

    case Create = 2200
    case GoBack = 2201
}
}

sample function using enum type as input parameter

使用枚举类型作为输入参数的示例函数

func showCFScreenForEnumType(cFooter: CFScreen.CFScreen_Groups) {

    //Group Related
    switch cFooter {

    case .Create:
        print("Show Create Group")
        break

    case .GoBack:
        print("Show Go Back Screen")
        break
    }
}

func showCFScreenForEnumType(cFooter: CFScreen.CFScreen_Newsfeed) {

    //Group Related
    switch cFooter {

    case .Newsfeed_01:
        print("Show News 01")
        break

    case .Newsfeed_02:
        print("Show News 02")
        break

    case .Newsfeed_03:
        print("Show News 03")
        break

    case .Newsfeed_04:
        print("Show News 04")
        break

    case .Newsfeed_05:
        print("Show News 05")
        break

    case .Newsfeed_06:
        print("Show News 06")
        break

    case .Newsfeed_07:
        print("Show News 07")
        break

    case .Newsfeed_08:
        print("Show News 08")
        break
    }
}

Calling this functions as follows

调用此函数如下

let selCFScreenG = CFScreen.CFScreen_Groups.Create
    showCFScreenForEnumType(selCFScreenG)

let selCFScreenNF = CFScreen.CFScreen_Newsfeed.Newsfeed_01
    showCFScreenForEnumType(selCFScreenNF)

Taken Reference from link: http://www.codingexplorer.com/enumerations-swift/

从链接中获取参考:http://www.codingexplorer.com/enumerations-swift/

My question is how i can write a function that will accepting enum types generically so that i can merge these below two functions into one

我的问题是我如何编写一个通用接受枚举类型的函数,以便我可以将这两个函数合并为一个

func showCFScreenForEnumType(cFooter: CFScreen.CFScreen_Groups)
func showCFScreenForEnumType(cFooter: CFScreen.CFScreen_Newsfeed)

1 个解决方案

#1

You could create a generic type constraint to some protocol, say MyCFScreenEnums, to which only the two enums in CFScreen conforms, and within the function that makes use of this (type constrained) generic, perform attempted type conversion to one of the two enums CFScreen.CFScreen_Newsfeed/CFScreen.CFScreen_Newsfeed. Since only these two conform to MyCFScreenEnums, one of these type conversions is guaranteed to be successful due to the type constraint of the generic (say T) to MyCFScreenEnums.

您可以为某些协议创建泛型类型约束,例如MyCFScreenEnums,只有CFScreen中的两个枚举符合,并且在使用此(类型约束)泛型的函数内,执行尝试类型转换到两个枚举CFScreen之一.CFScreen_Newsfeed / CFScreen.CFScreen_Newsfeed。由于只有这两个符合MyCFScreenEnums,由于通用(比如T)到MyCFScreenEnums的类型约束,因此保证其中一个类型转换成功。

protocol MyCFScreenEnums { }
extension CFScreen.CFScreen_Newsfeed : MyCFScreenEnums {}
extension CFScreen.CFScreen_Groups : MyCFScreenEnums {}

func showCFScreenForEnumType<T: MyCFScreenEnums>(cFooter: T) {
    if let newsfeed = cFooter as? CFScreen.CFScreen_Newsfeed {
        switch newsfeed {
        case .Newsfeed_01: print("Show News 01")
        case .Newsfeed_02: print("Show News 02")
        case .Newsfeed_03: print("Show News 03")
        case .Newsfeed_04: print("Show News 04")
        case .Newsfeed_05: print("Show News 05")
        case .Newsfeed_06: print("Show News 06")
        case .Newsfeed_07: print("Show News 07")
        case .Newsfeed_08: print("Show News 08")
        }
    }
    else if let groups = cFooter as? CFScreen.CFScreen_Groups {
        switch groups {
        case .Create: print("Show Create Group")
        case .GoBack: print("Show Go Back Screen")
        }
    }
}

/* Example usage */
let foo = CFScreen.CFScreen_Newsfeed.Newsfeed_03
let bar = CFScreen.CFScreen_Groups.Create
showCFScreenForEnumType(foo) // "Show News 03"
showCFScreenForEnumType(bar) // "Show Create Group"