没有给出与 Dictionary<string, string>.Add(string, string) 所需的形式参数“value”相对应的参数 [重复]答案

【问题标题】：There is no argument given that corresponds to the required formal parameter 'value' of Dictionary<string, string>.Add(string, string) [duplicate]没有给出与 Dictionary<string, string>.Add(string, string) 所需的形式参数“value”相对应的参数 [重复]
【发布时间】：2018-04-17 08:27:34
【问题描述】：

我尝试用这种方式构造Dictionary<string, Dictionary<string, string>>的实例，

Dictionary<string,  Dictionary<string, string>> PredictiveTable =
            new Dictionary<string, Dictionary<string, string>>(){
                {"+", new Dictionary<string, string>() {"E","error"}},
                {"*", new Dictionary<string, string>() {"E","error"}},
                {"i", new Dictionary<string, string>() {"E","E->TK"}},
                {"(", new Dictionary<string, string>() {"E","E->TK"}},
                {")", new Dictionary<string, string>() {"E", "error"}},
                {"#", new Dictionary<string, string>() {"E", "error"}}
};

但是编译器只是告诉错误信息

CS7036 C# 没有给出与所需形式相对应的参数 Dictionary.Add(string, string)
的参数'value'

我之前尝试搜索错误提示，但找不到解决方法。

如果有人可以帮助我，我将不胜感激。

【问题讨论】：

标签： c# dictionary

【解决方案1】：

Dictionary<string, Dictionary<string, string>> PredictiveTable =
            new Dictionary<string, Dictionary<string, string>>(){
                {"+", new Dictionary<string, string>() {{"E","error"}}},
                {"*", new Dictionary<string, string>() {{"E","error" }}},
                {"i", new Dictionary<string, string>() {{ "E","E->TK"}}},
                {"(", new Dictionary<string, string>() {{"E","E->TK"}}},
                {")", new Dictionary<string, string>() {{"E", "error"}}},
                {"#", new Dictionary<string, string>() {{ "E", "error"}}}
};

new Dictionary<string, string>() 期望 KeyPairValues 的 collection 用于初始化（就像您对外部 Dictionary 所做的那样）。你只通过了一个。

所以

new Dictionary<string, string>() {"E","error"}

变成

new Dictionary<string, string>() {
    {"E","error"}
}

【讨论】：

【解决方案2】：

尝试遵循此语法。

在您的代码中，您在使用值初始化子字典时缺少 {} 括号。你对 out Dictionary 但不是在 inner 中所做的相同。

Dictionary<string, Dictionary<string, string>> dict = new Dictionary<string, Dictionary<string, string>>() {
                {"Key1", new Dictionary<string, string>() { { "SubKey1","Value1"} } },
                {"Key2", new Dictionary<string, string>() { { "SubKey2","Value2"} } }
            };

按照此操作后，您的字典将如下所示

Dictionary<string, Dictionary<string, string>> PredictiveTable =
            new Dictionary<string, Dictionary<string, string>>(){
                {"+", new Dictionary<string, string>() {{"E","error"}}},
                {"*", new Dictionary<string, string>() {{"E","error" }}},
                {"i", new Dictionary<string, string>() {{ "E","E->TK"}}},
                {"(", new Dictionary<string, string>() {{"E","E->TK"}}},
                {")", new Dictionary<string, string>() {{"E", "error"}}},
                {"#", new Dictionary<string, string>() {{ "E", "error"}}}
};

【讨论】：

【解决方案3】：

        Dictionary<string,  Dictionary<string, string>> PredictiveTable =
                new Dictionary<string, Dictionary<string, string>>(){
                    {"+", new Dictionary<string, string>() {["E"] = "error"}},
                    {"*", new Dictionary<string, string>() {["E"] = "error"}},
                    {"i", new Dictionary<string, string>() {["E"] = "E->TK"}},
                    {"(", new Dictionary<string, string>() {["E"] = "E->TK"}},
                    {")", new Dictionary<string, string>() {["E"] = "error"}},
                    {"#", new Dictionary<string, string>() {["E"] = "error"}}
    };

【讨论】：