Question

I want to do do something like this :

Type t=typeof(int?);

or

Type t=typeof(MemoryStream);

However the parameter is string (“int?”,”MemoryStream”,etc) and it is not in assembly qualified type name so Type.GetType(string) won’t work.

The reason I need to get type is because I’m doing simple code generator application and it need to handle value & reference type different way, and also if type is Enumerable it will iterate and do specific operation.

Do you have any clue about this?

Answer 1

Well, you could create a compiler-on-the-fly, like so:

string getTypeHack = @"using System; public static class TypeHacker {{ public static Type GetThisType() {{ return typeof({0}); }} }}";

CodeDomProvider codeProvider = CodeDomProvider.CreateProvider("CSharp");
CompilerParameters parameters = new CompilerParameters();
parameters.GenerateInMemory = true;
parameters.GenerateExecutable = false;
CompilerResults results = codeProvider.CompileAssemblyFromSource(parameters, string.Format(getTypeHack, "int"));

Type hacker = results.CompiledAssembly.GetType("TypeHacker");
MethodInfo hack = hacker.GetMethod("GetThisType");
Type actualType = (Type)hack.Invoke(null, null);

… but this is probably a really bad idea. You need a new in-memory assembly for each type you are testing. Some problems off the top of my head:

• You’re going to have memory-leakage-city with the code above; you would need to mitigate that.
• It’s going to be slow.
• It’s ugly.
• You still may have assembly resolution issues, depending on which types you are allowing.

(I might actually downvote myself for suggesting this…) :^)

Is there any way to refactor the application to pass a Type? It’s going to make your life so much easier.