Reflection

Question

I have a dll that I am trying to create an instance of but is saying the protection level is high. I've read that I can use reflection to create this instance. Anyone know the proper syntax for doing this?

Vulpes · Answer

If you're talking here about loading a .NET dll, dynamically, at runtime and then instantiating its types, then here's some sample code.
First create this simple dll, marc_test.dll :
// marc_test.cs
using System;
public class MyClass {    public void MyMethod()    {       Console.WriteLine("Hello from MyMethod");    } }
internal class MyClass2 {    internal void MyMethod2()    {       Console.WriteLine("Goodbye from MyMethod2");    } }
Now create the following executable which loads the dll at runtime (place the dll in the same folder as the executable to facilitate this):
using System; using System.Reflection;
class Program {    static void Main()    {       Assembly a = Assembly.LoadFrom("marc_test.dll");       Type t = a.GetType("MyClass");       object obj = Activator.CreateInstance(t);       BindingFlags bf = BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod;       t.InvokeMember("MyMethod", bf, null, obj, null);
Type t2 = a.GetType("MyClass2");       object obj2 = Activator.CreateInstance(t2);       BindingFlags bf2 = BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.InvokeMethod;       t2.InvokeMember("MyMethod2", bf2, null, obj2, null);
Console.ReadKey();    } }
The output,as expected, is:
Hello from MyMethod Goodbye from MyMethod2
Notice a couple of points here:
1.  Although MyClass2 is internal to the dll, we are still able to create an instance of it.
2. Also, even though MyClass2.MyMethod2 is an internal method, we can still call it just by changing the BindingFlags variable to include BindingFlags.NonPublic rather than BindingFlags.Public.