无法将'System.Collections.Generic.Dictionary<string,System.Collections.Generic.List<string>&g

Question

class Program
{
    static void Main(string[] args)
    {           
        Dictionary<string, string> questionDict = new Dictionary<string, List<string>>(); //creating animal dict
        List<string> removeKeys = new List<string>(); //so I can remove the keys if need be
        questionDict.Add("Does it have whiskers?", "cat");
        questionDict.Add("Does it purr?", "cat");
        questionDict.Add("Does it bark?", "dog");
        while (true)
        {
            foreach (KeyValuePair<string, string> kvp in questionDict)//checks for each value of kvp in questionDict
            {
                Console.WriteLine("Computer: {0}", kvp.Key); //prints kvp, or in this instance, the question
                string userInput = Console.ReadLine();
                if (userInput.ToLower() == "yes") //if yes THEN
                {
                    Console.WriteLine("VAL: {0}", kvp.Value); //writes the value
                }
                else
                {
                    removeKeys.Add(kvp.Key); //adds the wrong animals to the removeKeys list
                }
            }
            foreach(string rKey in removeKeys)
            {
                questionDict.Remove(rKey); //removes all the values of rKey in removeKeys from questionDict
            }
        }
    }
}

new Dictionary<string, List<string>>();给了我错误。有什么帮助吗？我试图让我的字典每个键有多个值，我被告知这只能通过List<string>来实现。

Answer 1

将声明更改为：

Dictionary<string, List<string>> questionDict = new Dictionary<string, List<string>>();

被赋值的变量的泛型参数必须与您正在实例化的参数匹配。当然，类型也必须匹配(它已经匹配了(。请确保对代码的其他适用部分(如foreach循环定义(进行此更正。

请注意，如果你喜欢var(即使你不喜欢，这也是可以使用的更好的地方之一(，你可以写：

var questionDict = new Dictionary<string, List<string>>();

哪个更短，更难搞砸！