Where should I put my top level code?

Question

Hi

I'v got with my program this far to start using top level code.

If you look at my scheme you can see the top level is program:

http://tempuri.org/tempuri.html

I need to know where should I put the exchangeCar, login, logout method.

I tried to put them in program.cs, but it gives me "cannot declare instance members in static class" error

I tried to put it in the form.cs but this gives me some inconsistent accessibility error.

I want to know where should I put the methods? Program.cs, Form.cs or create another superclass?

Thank you

Sam Hobbs · Answer

The unwritten rule is that if you have a problem that is not answered after you have made a reasonable effort to find the answer then you request assistance from others. Actually you will find that rule stated explicitly one way or another in most programming forums. The answers to your questions are answered very well in books on the subject. So your questions will likely get the same response in most programming forums. Some might be more rude in telling you to read a book. Most will likely ignore the questions. If your questions were easily answered then there is a good chance they would get answers in these forums but it would unfortunately require too much time to give you a good answer. It seems to me that there are many existing applications that are so much like yours that there certainly are many resource available to you.

Suthish Nair · Answer

how you declaring your classes.. can you share the classes. Its a static class library all the methods are static.??

Moose Pickard · Answer

I do understand that I' m using your precious time don't get me wrong here. I appreciate your posts but this is all about inability nothing else. This topic and so many others I have posted. I have done almost all work on my program from my own reasoning logic and from other sources. So this should't be the area of accusations. I have asked many questions but the answers provided are riddles Yoda's thing. Read some books do it the other way etc but all miss the answer to the original question. I asked simple questions provided with all evidence: scheme flow etc (should be familiar to all programmers): . Where should I put this method? and Why this doesn't work?. You can reread the topic and see for yourself that only little good info is provided. The topic could have been only 2 post one. This is an issue of miscommunication and not paying attention. It just starts getting annoying that is all. I'm not new to the world of online forums I know the unwritten rules. But this experience is new for me. I don't need any feedback to this post because my post is already offtopic. This is not some prohibition I'm no moderator and am not that familiar with the rules. Thank you

Mahesh Chand · Answer

Moose .. it's not about inability. You may be a single young guy but many of us here have familities full time job and with a limited time we try to help others for FREE. So keep in mind get the hint and go do your work which you suppoed to do. We can only guide you. YOU ARE THE ONE WHO HAS TO DO THE ACTUAL WORK.

Moose Pickard · Answer

Hahaha The inability to answer simple questions. I don't want riddles. I thank you for your reply but is of no use to me. I know about basic scope the methods are public. I want to kow why does this work: class CarRentalProgram { public List CarRental >CarRentals = new List CarRental >(); CarRental carRental1 = new CarRental (); public void CarTEST () { CarRentals.Add(carRental1); carRental1.AddUser( Moose  Pickard  Moose@gmail.com ); carRental1.AddCar( BMW  E36  5000); } } And this doesn't: class CarRentalProgram { public List CarRental >CarRentals = new List CarRental >(); CarRental carRental1 = new CarRental (); CarRentals.Add(carRental1); carRental1.AddUser( Moose  Pickard  Moose@gmail.com ); //This line gives me error carRental1.AddCar( BMW  E36  5000); // This line gives me error }

Mahesh Chand · Answer

To access a property or a method outside of the class you MUST make them public. I think as Sam said you need to look into fundamentals of classes and their scope of declaration. I suggest you download and read this book: Free Book : C# Programming for Beginners After that read more on classes here. Understanding Classes in C# Hope it helps! Cheers!

Moose Pickard · Answer

Hi Actually I am already doing it but with other names. I chose to create another class with the methods - CarRentalProgram. But one thing that troubles me is this error: ...is a 'field' but is used as a 'type'. I've got this code: class CarRentalProgram { public List CarRental >CarRentals = new List CarRental >(); CarRental carRental1 = new CarRental (); CarRentals.Add(carRental1); carRental1.AddUser( Moose  Pickard  Moose@gmail.com ); //This line gives me error carRental1.AddCar( BMW  E36  5000); // This line gives me error } I tried to instantiate some objects to test. But the error I described is given when I set some properties of the objects. What I did next is that I tried to put the code in a method. The error disappeared. Why is that so that I can't use the methods of these objects outside of the class's methods? Also you can see the List CarRentals I created. When I'm typing the name in it doesn't give me autocomplete. But when I do it inside a method it does. I am starting to see that there is some rule behind this. What is this? Thank you for your posts.

Mahesh Chand · Answer

As Sam said you need to think everything in terms of objects (classes) and their related functionality. So you should have a class called Car that represents a Car object. You should have a class called Cars or CarCollection that represents a collection of Cars. You can also have a class called CarHelper and this class can have all the cars related helper functionality including your exchangeCar method. You are going to create an instance of Car and other needed instances usually on the Form class. It is usually the Form's loaded event handler. Hope it helps!

Moose Pickard · Answer

Hi I have read MANY books about C# OOP Design Patterns Java C# PHP etcand this problem is spefic only to C#. (I haven't figured out where the form.cs program.cs are in the hierarchy) All I want to know is where should I put my ExchangeCar method? I expect a simple answer. I'll rephrase it. Where would you put it if You had this arhitecture to work with? I think the scheme is clear enough to make it understood that it is a program about CarRentals and exchange cars is about exchanging CARS between CarRentals. By the way I have one form in my program. And to add more clarity - this is my personal project I don't need the smoothness of the commercial project. This is just an experiment. I have one part of the answer: not in the program.cs. But the program.cs has the access point - the main method. And now you clarified that form.cs should have only form related stuff. But where do I create the instances then? For testing I mean. I have seen in books that they are put in form.cs. Thank you

Sam Hobbs · Answer

You need to think in terms of classes not source code files. For C# everything must be in a class. So if you have a method that is used in the form only and just one form then you can put the method in the form class or you can create a separate class either in the same source code file as the form class or you could create a class in a separate file. I am sorry if this is confusing. This is basic to C# and to object-oriented languages such as C#. Therefore it is explained very well in many books. So instead of someone trying to explain it all for you it would be better if you find something that someone has already written that explains it to many people. Find a book about C#. You might be able to find articles on this subject but you will certainly benefit from a book. There are various methodologies for developing applictions but I am not really familir with them. One way is to use a Data Access Layer (DAL) separate from the Business Logic Layer (BLL). There are many articles about that. Another way is using Entities and there are many articles about that too. Visual Studio has support for Entities but I don't know anything more on the subject. You should look for all the relevant articles that this web site offers. Look in Design & Architecture in C# and .NET and in .NET Best Practices .

Moose Pickard · Answer

Here is the flow: User logs in The list of cars get rendered. Now he checks the car he wants to rent. The ExchangeCar method gets called from the form button which submitts the necessery variables. This code is the highest level. It is basically CarRentalProgram class. It has CarRental objects which have Car and User objects etc. You can see from the scheme? Can you see it? I can see  http://tempuri.org/tempuri.html  but it is in flickr.

Mahesh Chand · Answer

What does this code do? Is this some code that is being shared in the entire application OR is it just a Form related? Definitely not put anything in Program.cs. Everything should be placed in Form1.cs (or whatever your form class name is). If you want to share this code from multiple Forms you need to search this site for how to share variables among multiple forms.