How can I get the unique values of an array in .net?

string[] OutputArray = MyArray.Distinct().ToArray();

int[] test = { 1, 2, 1, 3, 3, 4, 5 };
var res = (from t in test select t).Distinct<int>();
foreach (var i in res)
{
    Console.WriteLine(i);
}

1
2
3
4
5

string[] myarray = new string[] { "aaa", "bbb", "aaa" };
            Dictionary mydict = new Dictionary();
            foreach (string s in myarray) {
                if (!mydict.ContainsKey(s)) mydict.Add(s, s);
            }