Question

I have a dictionary and it’s type is Dictionary<int, fooClass> fooDic and another dictionary is Dictionary<int, string> barlist and I’m using this linq to return result

var foobarList = fooDic.Where(kvp => 
       !barlist.ContainsKey(((fooClass)kvp.Value)._fooID))
       .ToDictionary(kvp => kvp.Key, kvp => kvp.Value);

This will return result of fooDic type. But I need to type cast output as barlist(Dictionary<int, string>) type. How?

Answer 1

If it’s a rather simple transformation, the key is the last part of your

var foobarList = fooDic.Where(kvp => 
    !barlist.ContainsKey(((fooClass)kvp.Value)._fooID))
    .ToDictionary(kvp => kvp.Key, kvp => kvp.Value);

statement. Where you currently use kvp => kvp.Value, you substitute that for kvp => kvp.Value._foobarValue.

Edited for “full” solution in accordance with OP’s comments.