c＃获取泛型类中泛型类型参数的名称

Question

I'm trying to get the type parameter's name ( ClassName<TypeParameterName> ) of geneic class from the class type.

for example something like this:

class MyClass<Type1>
{
    public Type data;
}
static void Main()
{
    Console.WriteLine(typeof(MyClass<int>).GetTypeParameterName());
    //prints: Type1
}

I searched a lot and didn't find anything about how to do this. the only thing I thought of was using StreamReader and read the whole .cs file and find the type there in the text. But is there any faster/cleaner way to do this?

Note: I'm not trying to get the type of Type1 I'm trying to get the string "Type1".

Answer 1

In your example, you already set the generic type parameter to int , so you won't get your Type1 .

Try this:

class MyClass<Type1>
{
    public Type data;
}
static void Main()
{
    Console.WriteLine(typeof(MyClass<>).GetGenericArguments()[0].Name);
    //prints: Type1
}

Answer 2

Try the following:

       .
       .
       .
      //Create and object of the relevant generic class
       ClassName<string> d = new ClassName<string>();

       // Get a Type object representing the constructed type.
       Type constructed = d.GetType();

       Type generic = constructed.GetGenericTypeDefinition();
       DisplayTypeInfo(generic);
    }

    private static void DisplayTypeInfo(Type t)
    {
        Console.WriteLine("\r\n{0}", t);
        Console.WriteLine("\tIs this a generic type definition? {0}", 
            t.IsGenericTypeDefinition);
        Console.WriteLine("\tIs it a generic type? {0}", 
            t.IsGenericType);
        Type[] typeArguments = t.GetGenericArguments();
        Console.WriteLine("\tList type arguments ({0}):", typeArguments.Length);
        foreach (Type tParam in typeArguments)
        {
            Console.WriteLine("\t\t{0}", tParam);
        }
    }

Source: https://msdn.microsoft.com/en-us/library/system.type.getgenerictypedefinition(v=vs.110).aspx

Answer 3

I say let's make it a nice extension method that works for all types, which seems to fit your scenario of code analysis.

static class TypeExtensions {
    public static IEnumerable<string> GetGenericTypeParameterNames(this Type type) {
        if (type.IsGenericTypeDefinition) {
            return type.GetGenericArguments().Select(t => t.Name);
        } else if (type.IsGenericType) {
            return type.GetGenericTypeDefinition().GetGenericArguments().Select(t => t.Name);
        } else {
            return Enumerable.Empty<string>();
        }
    }
}

Now typeof(MyClass<int>).GetGenericTypeParameterNames() is Type1 , while typeof(int).GetGenericTypeParameterNames() is empty. Use .Where() with whatever criterion you please to weed out "bad" names.