How to pass className to a method which gets generic type as a parameter in C#

Question

I have lots of classes reflecting my screen Repository from White/UIAutomation. To use repository I need to create lots of classes that reflect screens of my application windows.

To create a repository I use the following method:

var repoReport = repository.Get<MyClassRepresentingWindow>("WindowTitle", 
InitializeOption.WithCache);

it passes a generic type which is a Class I prepared.

What I want to do is to create a Dictionary(stringClassName, string windowTitle) or any Map to pass to that method. The problem is can't pass className like in Java ClassForName.

I tried System.Activator but without any success.

Object configObj = System.Activator.CreateInstance(c);
Type c = System.Type.GetType("Namespace.MyClassRepresentingWIndow");

var myClass = System.Reflection.Assembly.GetExecutingAssembly().CreateInstance("Namespace.MyClassRepresentingWIndow");

Type type = assembly.GetType("Namespace.MyClassRepresentingWIndow");
object obj = Activator.CreateInstance(type);

var repoReport = repository.Get<c>("WindowTitle", 
InitializeOption.WithCache);

var repoReport = repository.Get<c.Name>("WindowTitle", 
InitializeOption.WithCache);

Update1 Guys, I'm not sitting in front of the code but I'll try to make my question less complicate.

This is a method which I found in the White repository that I think I use: https://github.com/petmongrels/white/blob/itemsmap/Components/Repository/Source/ScreenRepository.cs

public virtual T Get<T>(string title, InitializeOption option) where T : AppScreen
    {
        ClearClosedScreens();
        AppScreen screen;
        var repositoryCacheKey = new ScreenRepositoryCacheKey(title, typeof (T));
        if (!screenCache.TryGetValue(repositoryCacheKey, out screen))
        {
            Window window = applicationSession.Application.GetWindow(title, IdentifiedOption<T>(option));
            screen = GetScreen<T>(window);
            screenCache.Add(repositoryCacheKey, screen);
        }

        if (screen != null)
            sessionReport.Next(typeof (T));
        return (T) screen;
    }

As I remember VS displayed .Get as a .Get<"class" type>. I'm sorry I can't express myself better. Please have a patient with me because I'm not familiar with this terminology.

Update2

At the end I want to get something like this:

var repoReport1 = repository.Get<MyClassRepresentingWindow1>("WindowTitle", InitializeOption.WithCache);
var repoReport1 = repository.Get<MyClassRepresentingWindow2>("WindowTitle", InitializeOption.WithCache);
var repoReport1 = repository.Get<MyClassRepresentingWindow3>("WindowTitle", InitializeOption.WithCache);

And I have a code of MyClassRepresentingWindow{1,2,3}. I just don't know how to pass class name to Get method. On input I have a string name of this class. On output I want to deliver something that this method .Get<T> can get. I hope you can understand me now.

I'm confused as to what you are trying to do. if you can narrow down your problem and remove the noise it may be more clear what you need to do. — Jason Meckley, Dec 22 '11 at 16:38
You can use Reflection. Check this post: http://stackoverflow.com/questions/232535/how-to-use-reflection-to-call-generic-method — Strillo, Dec 22 '11 at 16:39
How is Repository.Get working with the generic parameter? One would think it would be creating objects with Activator as well. — Steve Danner, Dec 22 '11 at 16:58
I updated text - I added a method code that I think I'm using. Guys I won't be able to check your advise/solution right now. I'll do that defiantly just after Christmas. Mary Christmas and a happy New Year! — Robert Gonciarz, Dec 24 '11 at 09:14

score 3 · Answer 1 · answered Dec 23 '11 at 03:48

In order to call this with a variable type argument, whose value is only known at run time, you need to use reflection. I assume that you know how to get the MethodInfo representing the repository's Get<T> method.

Once you have that, this example illustrates the basic idea how to use the MethodInfo object. The example assumes that the repository class is called Repo; change that as needed:

object InvokeGenericMethod(Repo repository, MethodInfo method, Type typeArg, string arg1, InitializeOption arg2)
{
    MethodInfo constructedMethod = method.MakeGenericMethod(typeArg);
    return constructedMethod.Invoke(repository, new object[] { arg1, arg2 });
}

You could make this more generic, of course, but that would have made the example less clear.

score 1 · Answer 2 · answered Dec 22 '11 at 17:42

I believe what you want is something like this:

    public string GetName<T>()
    {
        return typeof(T).Name;
    }

That causes the following unit test to pass (the "Basic Math" is just a type I had laying around in my scratch application):

    [TestMethod]
    public void Test_Of_Generic_Type_Name()
    {
        var myBuilder = new GenericNamer();

        Assert.AreEqual<string>("BasicMath", myBuilder.GetName<BasicMath>());
    }

You could also use the type's full name, assembly, etc. Here's some more information on what you can pull out of the Type class using reflection:

http://msdn.microsoft.com/en-us/library/system.type.aspx

Hi Erik, thanks for your answer but I think I need something opposite. On input I have a string name of my class which I know and I have a working code of this class. On output I want to deliver something that this method .Get accepts. I hope you know what I mean — Robert Gonciarz, Dec 24 '11 at 09:24

How to pass className to a method which gets generic type as a parameter in C#

2 Answers2