C#•2mo ago

Getting the typeof this to use in a generic method

I have a class with a method that requires a different class that has a generic method. How can I get the type of the first class to pass into the generic method?

public class Foo
{
  void GenericMethod<T> () {}
}

public class Bar
{
  void Pass (Foo foo)
  {
    // I want to get Bar to use as T but I'm unsure how to search for this problem and this doesn't work.
    Type T = this.GetType();
    foo.GenericMethod<T>();
  }
}

public class Foo
{
  void GenericMethod<T> () {}
}

public class Bar
{
  void Pass (Foo foo)
  {
    // I want to get Bar to use as T but I'm unsure how to search for this problem and this doesn't work.
    Type T = this.GetType();
    foo.GenericMethod<T>();
  }
}

7 Replies

sibber•2mo ago

foo.GenericMethod<Bar>

Holipop•2mo ago

If I have any class that extends Bar, will they have to override the method to pass their own type in or no? like if I had.. class Thing : Bar for context, I want Bar to be an abstract class and for anything that inherits it to have Pass work

sibber•2mo ago

ah generally the solution for that is this:

public class Bar<T> where T : Bar<T>
{
        bla bla
        foo.GenericMethod<T>();
}

public class Bar<T> where T : Bar<T>
{
        bla bla
        foo.GenericMethod<T>();
}

its not a perfect solution since you could pass another T that inherits bar but its the best you can do in C# for now

Holipop•2mo ago

Gotcha gotcha, thank you lots!

sibber•2mo ago

np $close

MODiX•2mo ago

If you have no further questions, please use /close to mark the forum thread as answered

SleepWellPupper•2mo ago

The pattern is called CRTP if you want to read more about it.

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Getting the typeof this to use in a generic method