定义Dictionary<string、Dictionary<string、int>>

Question

我试图在C#中定义字典对象的静态只读字典，并且不确定这是否是存储由1键和2值组成的对象的正确方法。这段代码不起作用，但它显示了我正在努力实现的目标的逻辑。

private static readonly Dictionary<string, Dictionary<string, int>> StudentMapping = new Dictionary<string, Dictionary<string, int>>
        {
            {"Liam", new Dictionary<string, int>{"broadway", 1}},
            {"Emily", new Dictionary<string, int>{"math", 1}}
        }

Answer 1

不确定这是否是存储由1键和2值组成的对象的正确方法。

若要为每个int键存储2个String值，请使用ValueTuple of (int, int) for TValue

C# has special-case syntax for using ValueTuple

private static readonly Dictionary<string,(int broadway, int math)> StudentMapping = new Dictionary<string,(int broadway, int math)>
{
    { "Liam" , ( broadway: 1, math: 1 ) },
    { "Emily", ( broadway: 1, math: 1 ) },
}

Answer 2

当您达到将字典嵌套为数据存储的地步时，很可能是时候使用类了

public class Student{

    public string Name {get; set;}
    public Dictionary<string, int> Grades {get;set;}
}

其用法可能是：

var students = new List<Student>(){
  new(){ 
      Name = "Emily", 
      Grades = new () { ["math"] = 1 , [ "english"] = 2 }   
}};