如何将键交换为值和将值交换为字典中的键

Question

伙计们，我想交换字典中的键和值

我的字典是这样的

public static void Main(string[] args)
{
Dictionary<int,int> dic = new Dictionary<int,int>{{1,10}, {2, 20}, {3, 30}};
}

现在我正在打印字典中的值

 foreach (KeyValuePair<int, int> kvp in dic)
{

    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
            Console.ReadKey();
}

在展示中我得到了这个

Key = 1, Value = 10
Key = 2, Value = 20
Key = 3, Value = 30

我想在键和值之间交换值..交换后答案应该是这样的

Key = 10, Value = 1
Key = 20, Value = 2
Key = 30, Value = 3

我做了 lambda 表达式，它改变了，但我需要一些其他方法来做..

Answer 1

假设值是唯一的，这可以工作：

var dic = new Dictionary<int,int>{{1,10}, {2, 20}, {3, 30}};

var dic2 = dic.ToDictionary(x => x.Value, x=> x.Key);

它实际上不会换边，你会得到一本新词典。

Answer 2

我想你会理解下面的代码：

namespace Swap
{
public class Class1
{
    public SortedDictionary<string, string> names;

    public void BeforeSwaping()
    {
        Console.WriteLine("Before Swapping: ");
        Console.WriteLine();
        names = new SortedDictionary<string, string>();
        names.Add("Sonoo", "srinath");
        names.Add("Perer", "mahesh");
        names.Add("James", "ramesh");
        names.Add("Ratan", "badri");
        names.Add("Irfan", "suresh");
        names.Add("sravan", "current");
        foreach (KeyValuePair<string, string> item in names)
        {

            Console.WriteLine("Key: {0}, Value: {1}", item.Key, item.Value);

        }
        Console.WriteLine();
    }

    public void AfterSwaping()
    {
        Console.WriteLine("After Swapping: ");
        Console.WriteLine();
        var key = names.Keys;
        var val = names.Values;

        string[] arrayKey = new string[key.Count];
        string[] arrayVal = new string[val.Count];
        int i = 0;
        foreach (string s in key)
        {
            arrayKey[i++] = s;
        }
        int j = 0;
        foreach (string s in val)
        {
            arrayVal[j++] = s;
        }
        names.Clear();
        //Console.WriteLine(arrayVal[0] + " " + arrayKey[0]);
        for (int k = 0; k < (arrayKey.Length + arrayVal.Length) / 2; k++)
        {
            names.Add(arrayVal[k], arrayKey[k]);
        }
        foreach (KeyValuePair<string, string> s in names)
        {
            Console.WriteLine("key:"+s.Key + ", "+"value:" + s.Value);
        }
    }
    public static void Main(string[] args)
    {
        Class1 c = new Class1();
        c.BeforeSwaping();
        c.AfterSwaping();
        Console.ReadKey();
    }
  }
}

如何将键交换为值和将值交换为字典中的键

how to swap keys into values and values into key in a dictionary

c#

swap

dictionary