arrays - 从字符串中获取结构属性 - swift

Question

我声明了一个具有 4 个属性(informationA、informationB、informationC、informationD)的结构。

我还声明了一个这样的数组(该数组包含一些 my_struct 属性的名称作为 "strings" :

let keys = ["informationA", "informationB", "informationC"]

现在我想要一个 for 循环遍历 "keys"-array 并打印出当前字符串的结构属性值 ( “信息 A”、“信息 B”、“信息 C”)。

---

struct my_struct {
    var informationA = "test"
    var informationB = "test...test"
    var informationC = "test...test"
    var informationD = "test...test..."
}



func getInformation() {
   let keys = ["informationA", "informationB", "informationC"]
   for i in keys {
       print(my_struct.i) // ERROR: Type 'my_struct' has no member 'i'

      // should print ---> "test", "test...test", "test...test"
   }
}

使用上面的代码我得到了这个错误错误:类型'my_struct'没有成员'i'。有没有办法避免此消息并获得我想要的结果？

Answer 1

你要找的是反射(reflection):

struct MyStruct {
    var informationA = "test"
    var informationB = "test...test"
    var informationC = "test...test"
    var informationD = "test...test..."
}

func getInformation() {
    let my_struct = MyStruct()
    let keys = ["informationA", "informationB", "informationC"]
    let m = Mirror(reflecting: my_struct)
    let properties = Array(m.children)

    for k in keys {
        if let prop = properties.first(where: { $0.label == k }) {
            print(prop.value)
        }
    }
}