Create Generic Method in C#

Question

I have the following structure:

public enum MyTypes
{
    Type1 = 1, 
    Type2 = 2,
    Type3 = 3
}

public abstract class class1
{
   int id;
   string name;
   MyType type;
}

public class class2 : class1
{

}


public class class3 : class1
{

}

public class class4 : class1
{

}

now what I want to do is to make a generic method , I want to give it the type of object say class 3 and it will create object from class 3 and define it's variables and return it to be able to add it to a list of class1

like that

private class1 myFunction (MyType t , int id , string name)
{
    T obj = new T();
    obj.type = t ;
    obj.id = id ;
    obj.name = name;
    return obj;
}

how to create this generic method ?

please Help me as soon as you can

Thanks in Advance

Answer 1

As Danny Chen says in his answer, you will have to modify your class definitions a little for it to work, then you could do something like the following:

public T myFunction<T>(int id, string name) where T : class1, new()
{
    T obj = new T();
    obj.id = id;
    obj.name = name;
    return obj;
}

This generic method requires type parameter T to be derived from class1 and also to have a parameter-less constructor -- that's what the where T : class1, new() means.

Since id and name properties are defined through the class1 base class, you can then set these to whatever was passed into myFunction via its parameters.

---

Some more things to note about class1:

• Consider making class1 an interface instead of an abstract class, as it doesn't contain any functionality.
• id, name, type need to be public if you actually want to be able to access them.
• Usually, fields aren't actually exposed as public. Consider using properties instead for that purpose.

Answer 2

No, it's impossible, because all these classes are abstract (can't be instantiated). We can't create an instance of an abstract class.