Cannot access a non-static member of outer type via nested type

Question

I have error

Cannot access a non-static member of outer type 'Project.Neuro' via nested type 'Project.Neuro.Net'

with code like this (simplified):

class Neuro
{
    public class Net
    {
        public void SomeMethod()
        {
            int x = OtherMethod(); // error is here
        }
    }

    public int OtherMethod() // its outside Neuro.Net class
    {
        return 123;  
    }
}

I can move problematic method to Neuro.Net class, but I need this method outside.

Im kind of objective programming newbie.

Thanks in advance.

Seems pretty obvious - OtherMethod is a member of another type. The fact that it's nested does not mean the methods are inherited. — D Stanley
– D Stanley, Commented May 1, 2013 at 15:19
See this SO answer for more info: stackoverflow.com/a/5393472/1451531 — Splendor
– Splendor, Commented May 1, 2013 at 15:21

D Stanley · Accepted Answer · 2013-05-01 15:23:16Z

21

The problem is that nested classes are not derived classes, so the methods in the outer class are not inherited.

Some options are

Make the method static:

class Neuro
{
    public class Net
    {
        public void SomeMethod()
        {
            int x = Neuro.OtherMethod(); 
        }
    }

    public static int OtherMethod() 
    {
        return 123;  
    }
}

Use inheritance instead of nesting classes:

public class Neuro  // Neuro has to be public in order to have a public class inherit from it.
{
    public static int OtherMethod() 
    {
        return 123;  
    }
}

public class Net : Neuro
{
    public void SomeMethod()
    {
        int x = OtherMethod(); 
    }
}

Create an instance of Neuro:

class Neuro
{
    public class Net
    {
        public void SomeMethod()
        {
            Neuro n = new Neuro();
            int x = n.OtherMethod(); 
        }
    }

    public int OtherMethod() 
    {
        return 123;  
    }
}

answered May 1, 2013 at 15:23

D Stanley

153k12 gold badges190 silver badges257 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Kamil Over a year ago

I made my method static. Now im wondering how shall I reorganize my classes... maybe its good subject for another question.

vlad · Accepted Answer · 2013-05-01 15:27:22Z

2

you need to instantiate an object of type Neuro somewhere in your code and call OtherMethod on it, since OtherMethod is not a static method. Whether you create this object inside of SomeMethod, or pass it as an argument to it is up to you. Something like:

// somewhere in the code
var neuroObject = new Neuro();

// inside SomeMethod()
int x = neuroObject.OtherMethod();

alternatively, you can make OtherMethod static, which will allow you to call it from SomeMethod as you currently are.

edited May 1, 2013 at 15:27

answered May 1, 2013 at 15:20

vlad

4,8082 gold badges32 silver badges36 bronze badges

1 Comment

vlad Over a year ago

@Kamil don't worry about it, D Stanley's answer is more complete anyway.

T.S. · Accepted Answer · 2013-05-01 15:32:11Z

0

Even though class is nested within another class, it is still not obvious which instance of outer class talks to which instance of inner class. I could create an instance of inner class and pass it to the another instance of outer class. Therefore, you need specific instance to call this OtherMethod().

You can pass the instance on creation:

class Neuro
{
    public class Net
    {
        private Neuro _parent;
        public Net(Neuro parent)
        {
         _parent = parent;
        }
        public void SomeMethod()
        {
            _parent.OtherMethod(); 
        }
    }

    public int OtherMethod() 
    {
        return 123;  
    }
}

edited May 1, 2013 at 15:32

answered May 1, 2013 at 15:23

T.S.

19.6k11 gold badges70 silver badges96 bronze badges

Comments

Tarık Özgün Güner · Accepted Answer · 2014-07-17 12:10:41Z

0

I think making an instance of outer class in inner class is not a good option because you may executing business logic on outer class constructor. Making static methods or properties is better option. If you insist making an instance of outer class than you should add another parameter to outer class contructor that not to execute business logic.

answered Jul 17, 2014 at 12:10

Tarık Özgün Güner

1,08110 silver badges10 bronze badges

Comments

Razvan Trufin · Accepted Answer · 2025-11-02 12:05:49Z

-1

you acces a methode of a class from other class you can not do this.

answered Nov 2 at 12:05

Razvan Trufin

1

1 Comment

Community Nov 2 at 13:31

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center.

Collectives™ on Stack Overflow

Cannot access a non-static member of outer type via nested type

5 Answers 5

1 Comment

1 Comment

Comments

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

1 Comment

1 Comment

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related