元组列表到该元组列表C＃中的第一个元素列表

Question

In Dictionary I can get a list of its Key / Values like in the below code:

    Dictionary<string, string> dictionary = new Dictionary<string, string>();
    List<string> list_of_first_elements = new List<string>();
    list_of_first_elements = new List<string> (dictionary.Keys);

Is there an attribute/method can do same with List<Tuple> without looping over the list and add its first/second elements? Something like that:

        List<Tuple<string, string>> list_of_tuples = new List<Tuple<string, string>>();
        list_of_first_elements = """SomeCode""";

Answer 1

正如@KlausGütter和@ 2kay提到的那样，我使用LINQ来做到这一点，它的性能几乎可以遍历整个List但是它显然更加清晰，下面是代码：

list_of_first_elements = list_of_tuples.Select(_ => _.Item1).ToList();