Using string.Join to flatten dictionary of strings, ordered by value.

stringjoin

string res = "";
var displayOrder = new Dictionary<string, int>(){{"string 2",2},{"string 1",1},{"string 3",3}};
res= string.Join(" - ",displayOrder.OrderBy(x => x.Value).Select(x=>x.Key));

// dump to LINQPad
res.Dump();