C# Dynamic select List of strings

You need to cast the items, like so:

List<string> things = objects.Select(x => x.nameref.ToString()).Cast<string>().ToList();

The reason why it's not recognizing that ToString() returns a string is that it's called on a dynamic object, and the method binding is done at runtime, not compile time.

Although Rob's answer works fine, let me suggest an alternative: Cast nameref to the correct type (replace (object) by a more specific cast, if you happen to know the type of nameref):

List<string> things = objects.Select(x => ((object)x.nameref).ToString()).ToList();

The advantage of that solution is that ToString is statically resolved. Thus, the method call is

• guaranteed to return string, since the compiler knows that you are calling Object.ToString() (or an overridden variant thereof) and

• faster and cleaner. This solution keeps dynamic resolution to the absolute minimum needed (i.e., the resolution of x.nameref). Typos in the call to ToString are caught by the compiler.

(Of course, if the type of nameref happens to be string, you can just drop the call to ToString(), making your code even cleaner and shorter.)

You could try using Cast, like so:

List<string> things = objects.Select(x => x.nameref).Cast<string>().ToList();

You could also try casting in the Select itself:

List<string> things = objects.Select(x => x.nameref as string).ToList();