Question

我试过了：

endResult = tempResult.Where(x => x.Key.Equals(nameOfMyList))
                      .SelectMany(wert => wert as List<MyCustomClass>)
                      .Cast<Dictionary<string, List<MyCustomClass>>>().ToDictionary(); //error "can not convert type"

endResult是Dictionary<string, List<MyCustomClass>>。

tempResult是Dictionary<string, Dictionary<string, List<MyCustomClass>>>。

这里有什么问题？

更新：

抱歉，我写的endResult是Dictionary<string, List<MyCustomClass>> 而不是 Dictionary<string, Dictionary<string, List<MyCustomClass>>>（已更新）

实际上我想从Dictionary<string, List<MyCustomClass>>中提取Dictionary<string, Dictionary<string, List<MyCustomClass>>>，转换类型，广告

Answer 1

您的.SelectMany(wert => wert as List<MyCustomClass>)会返回一个枚举器，返回List<MyCustomClass>的实例。您正尝试将该列表强制转换为Dictionary<string, List<MyCustomClass>>。这是不可能的，因为这些类型不可交换。

您必须自己确定要查找的转换路径。可以创建一个字典，但你必须自己想出一个密钥（必须是唯一的）：

.SelectMany(wert => wert as List<MyCustomClass>)
.ToDictionary( k => whatEverYourKeyIs
             , v => v /* this is the list */
             )

Answer 2

我认为你不懂字典。检查此示例：

var foo = new Dictionary<string, Dictionary<string, List<MyCustomClass>>>();
...
// Add some content to foo.
...

string nameOfMyList = ""; // Something that exists as a key in foo.

Dictionary<string, List<MyCustomClass>> result = foo[nameOfMyList];

如何将`Dictionary <string，dictionary <string，=“”list <mycustomclass =“”>＆gt;＆gt;`转换为`Dictionary <string，list <mycustomclass =“”>＆gt; `

2 个答案: