c# - 连接两个具有相同键记录的字典

Question

我想合并两个词典。当我尝试这个时，我收到关于重复键的错误。如何合并两个具有相同键的字典？

class Program
{
    static void Main(string[] args)
    {
        Dictionary<Class1.Deneme, List<string>> dict1 = new Dictionary<Class1.Deneme, List<string>>();
        Dictionary<Class1.Deneme, List<string>> dict2 = new Dictionary<Class1.Deneme, List<string>>();
        Dictionary<Class1.Deneme, List<string>> dict3 = new Dictionary<Class1.Deneme, List<string>>();

        List<string> list1 = new List<string>() { "a", "b" };
        List<string> list2 = new List<string>() { "c", "d" };
        List<string> list3 = new List<string>() { "e", "f" };
        List<string> list4 = new List<string>() { "g", "h" };

        dict1.Add(Class1.Deneme.Buyer, list1);
        dict2.Add(Class1.Deneme.Buyer, list2);
        dict3 = dict1.Concat(dict2).ToDictionary(kvp => kvp.Key, kvp => kvp.Value);

        Console.Read();
    }
}

public class Class1
{
    public enum Deneme
    { 
        Customer=1, 
        Buyer=2,
        Supplier=3
    }
}

Answer 1

按键对所有 KeyValuePairs 进行分组。然后通过选择组键作为键并将扁平值作为值将这些组转换为字典(如果您不想要重复的字符串，也可以在 ToList() 之前应用 Distinct() ):

dict1.Concat(dict2)
     .GroupBy(kvp => kvp.Key) // thus no duplicated keys will be added
     .ToDictionary(g => g.Key, g => g.SelectMany(kvp => kvp.Value).ToList());