创建一个以键为列表的字典(字符串) [英] create a dictionary with key as list(of string)

问题描述

需要创建一个字典，其中的键是列表(字符串)或字符串数​​组

need to create a dictionary where keys are list(Of String) or array of string

我找到了此链接 将C#列表作为字典键

但是我需要帮助来了解如何使用列表(字符串)

but i need an help to understand how to do it with list(of String)

Class test
    Sub TryTest()
        myDict.Add(New List(Of String) From {"Huey", "Dewey"}, actions.Sleeping)
        myDict.Add(New List(Of String) From {"Dewey", "Louie"}, actions.Playing)

        Dim newList As New List(Of String) From {"Dewey", "Louie"}
        If myDict.ContainsKey(newList) Then
            MsgBox("myDict contains the list of String, as Key Value")
        Else
            MsgBox("myDict don't contains the list of String, as Key Value")
        End If
    End Sub

    Dim myDict As New Dictionary(Of List(Of String), actions)

End Class

Enum actions
    Sleeping
    Eating
    Studying
    Playing
End Enum

我希望包含键的字典输出.

I expected that the dictionary output that contains the key.

P.S.由于c#与vb.net十分接近，并且在网上有很多c#/vb.net转换器可以轻松翻译，因此，也欢迎c#帮助.

P.S. Since c# it's close to vb.net, and on the net there are lot's of c#/vb.net translators that translate easily, please, also c# help are appreciated.

更新(在 Jeppe Stig Nielsen 帮助之后，我试图实现一个继承EqualityComparer的类，但是它不起作用...也许我在语法上犯了错误...有人知道我的方法有什么问题吗?

UPDATE (after Jeppe Stig Nielsen helps, i tried to implement a class that inherits EqualityComparer, but it doesn't work... maybe i mistake something in syntax... do someone know what's wrong in my approach?

Class test
    Sub TryTest()
        myDict.Add(New List(Of String) From {"Huey", "Dewey"}, actions.Sleeping)
        myDict.Add(New List(Of String) From {"Dewey", "Louie"}, actions.Playing)

        Dim newList As New List(Of String) From {"Dewey", "Louie"}
        If myDict.ContainsKey(newList) Then
            MsgBox("myDict contains the list of String, as Key Value")
        Else
            MsgBox("myDict don't contains the list of String, as Key Value")
        End If

        Try
            myDict.Add(newList, actions.Eating)
        Catch ex As Exception
            MsgBox("myDict don't allow me to add an already present List (Of String), as Key Value")
        End Try

    End Sub

    Dim myDict As New Dictionary(Of List(Of String), actions)(New ListComparer)

End Class

Enum actions
    Sleeping
    Eating
    Studying
    Playing
End Enum

NotInheritable Class ListComparer
    Inherits EqualityComparer(Of List(Of String))

    Public Overrides Function Equals(ByVal x As List(Of String), ByVal y As List(Of String)) As Boolean
        Return StructuralComparisons.StructuralEqualityComparer.Equals(x, y)
    End Function

    Public Overrides Function GetHashCode(ByVal x As List(Of String)) As Integer
        Return StructuralComparisons.StructuralEqualityComparer.GetHashCode(x)
    End Function
End Class

推荐答案

使用

using System.Collections;
using System.Collections.Generic;

您可以创建类似的类

sealed class ListComparer : EqualityComparer<List<string>>
{
  public override bool Equals(List<string> x, List<string> y)
    => StructuralComparisons.StructuralEqualityComparer.Equals(x, y);

  public override int GetHashCode(List<string> x)
    => StructuralComparisons.StructuralEqualityComparer.GetHashCode(x);
}

，然后将其用作Dictionary<,>

myDict = new Dictionary<List<string>, Actions>(new ListComparer());

ListComparer类也可以是通用的sealed class ListComparer<T> : EqualityComparer<List<T>>.

评论后，我意识到StructuralEqualityComparer对List<string>不起作用(我曾想过)！它适用于string[]和Tuple<string, string, ...>之类的东西.因此，上述类需要更改为:

After comments, I realize that StructuralEqualityComparer does not work for List<string> (which I had thought)! It works for string[] and for stuff like Tuple<string, string, ...>. So the above class needs to be changed into:

sealed class ListComparer : EqualityComparer<List<string>>
{
  public override bool Equals(List<string> x, List<string> y)
    => StructuralComparisons.StructuralEqualityComparer.Equals(x?.ToArray(), y?.ToArray());

  public override int GetHashCode(List<string> x)
    => StructuralComparisons.StructuralEqualityComparer.GetHashCode(x?.ToArray());
}

我最初的尝试是错误的！

My original attempt was wrong!

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