如何在Swift 4中通过原始值获取枚举用例的名称? [英] How to get the name of an enumeration case by its raw value in Swift 4?

问题描述

具有一个Int类型的多个案例的枚举，如何按其rawValue打印案例名称?

Having an enumeration with multiple cases from type Int, how can I print the case name by its rawValue?

public enum TestEnum : UInt16{
case ONE    = 0x6E71
case TWO    = 0x0002
case THREE  = 0x0000
}

我正在通过rawValue访问枚举:

I am accessing the Enum by the rawValue:

print("\nCommand Type = 0x" + String(format:"%02X", someObject.getTestEnum.rawValue))
/*this prints: Command Type = 0x6E71
if the given Integer value from someObject.TestEnum is 28273*/

现在，我还想在十六进制值之后打印"ONE".

Now I additionally want to print "ONE" after the HEX value.

我知道以下问题:如何在Swift中获得枚举值的名称?但这有所不同，因为我想通过案例原始值而不是枚举值本身来确定案例名称.

I am aware of the Question: How to get the name of enumeration value in Swift? but this is something different because I want to determine the case name by the cases raw value instead of the enumeration value by itself.

所需的输出:

命令类型= 0x6E71，一个

推荐答案

由于枚举类型不是 String ，因此您无法以 String 的形式获得案例名称，因此您需要添加一种自己返回的方法…

You can't get the case name as as String as the enum's type isn't String, so you'll need to add a method to return it yourself…

public enum TestEnum: UInt16, CustomStringConvertible {
    case ONE = 0x6E71
    case TWO = 0x0002
    case THREE = 0x0000

    public var description: String {
        let value = String(format:"%02X", rawValue)
        return "Command Type = 0x" + value + ", \(name)"
    }

    private var name: String {
        switch self {
        case .ONE: return "ONE"
        case .TWO: return "TWO"
        case .THREE: return "THREE"
        }
    }
}

print(TestEnum.ONE)

// Command Type = 0x6E71, ONE

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