如何提取List <int> 来自字典 <int, string> ？

Question

I have a method that takes a List<int> , which is a list of IDs. The source of my data is a Dictionary<int, string> where the integers are what I want a list of. Is there a better way to get this than the following code?

var list = new List<int>();
foreach (var kvp in myDictionary)
{
    list.Add(pair.Key);
}

ExecuteMyMethod(list);

Answer 1

You could do

var list = myDictionary.Keys.ToList();

Or

var list = myDictionary.Select(kvp => kvp.Key).ToList();

Answer 2

是的，您可以在列表的构造函数中使用Keys集合：

List<int> list = new List<int>(myDictionary.Keys);

Answer 3

Like Guffa said that's some thing which is easy and elegant. or

List<int> nList = myDictionary.Keys.ToList<int>();