I get a compilation error and can't understand why

  • Thread starter Thread starter Tony Johansson
  • Start date Start date
T

Tony Johansson

What I want to accomplish is to use class FlowerNetDbContext in class
OrderRepository.
So when I call OrderRepository property in RepositoryFactory I return an
instans of OrderRepository and pass in dbContext
which is a FlowerNetDbContext.
OrderRepository is implementing IOrderRepository

So what do is this. I can't see any problem error in doinf this.
public IOrderRepository OrderRepository
{
get {return new OrderRepository(this.dbContext); ;}
}

The problem start when I do this row
private ProductRepository productRepository =
repositoryFactory.ProductRepository
in class ProductsDisplay below.

The error I get is this
Error 2 A field initializer cannot reference the non-static field, method,
or property 'Assignment_2.ProductsDisplay.repositoryFactory'
c:\datadrivenwebapplicationprogramming_2014\assignment_2\productsdisplay.aspx.cs
19 53 Assignment_2

I mean I instanciate RepositoryFactory and tell him to give me the
ProductRepository by calling the property that is named ProductRepository

So how can I fix this ?


public partial class ProductsDisplay : System.Web.UI.Page
{
private RepositoryFactory repositoryFactory = new RepositoryFactory();

private ProductRepository productRepository =
repositoryFactory.ProductRepositor
....
....
}


public class RepositoryFactory
{
private IOrderRepository orderRepo;
private FlowerNetDbContext dbContext;

public RepositoryFactory()
{
dbContext = new FlowerNetDbContext();
}

public IOrderRepository OrderRepository
{
get {return new OrderRepository(this.dbContext); ;}
}
}


public class OrderRepository : IOrderRepository
{
private FlowerNetDbContext dbContext;

public OrderRepository(FlowerNetDbContext context)
{
dbContext = context;
}
}


//Tony
 
The error I get is this
Error 2 A field initializer cannot reference the non-static field,
method, or property 'Assignment_2.ProductsDisplay.repositoryFactory'
c:\datadrivenwebapplicationprogramming_2014\assignment_2\productsdisplay.aspx.cs
19 53 Assignment_2
Click to expand...

You cannot use an instance variable to initialize another instance
variable. Why? Because the compiler can rearrange these - there is no
guarantee that repositoryFactory will be initialized before
productRepository

See
http://stackoverflow.com/questions/...erence-the-nonstatic-field-method-or-property

// Anders
 
But they are of the same type
How can I force to establish what I said in the mail

If I have an object in a class and want to use this object in other classes
how can I do that.
I want to share an object.

//Tony
 
But they are of the same type
How can I force to establish what I said in the mail

If I have an object in a class and want to use this object in other
classes how can I do that.
I want to share an object.

//Tony
Click to expand...
You didn't read the StackOverflow article did you ?
You need to put the initialization in the constructor of the class.
But since the code doesn't make any sense to me I can't help you...

Maybe someone else can make sense of the code can be more specific.

// Anders
PS! PLEASE don't top post! It makes it hard to follow the thread!
 
But they are of the same type
How can I force to establish what I said in the mail

If I have an object in a class and want to use this object in other
classes how can I do that.
I want to share an object.

//Tony
Click to expand...
You didn't read the StackOverflow article did you ?
You need to put the initialization in the constructor of the class.
But since the code doesn't make any sense to me I can't help you...

Maybe someone else can make sense of the code can be more specific.

// Anders
PS! PLEASE don't top post! It makes it hard to follow the thread!
 
You cannot use an instance variable to initialize another instance
variable. Why? Because the compiler can rearrange these - there is no
guarantee that repositoryFactory will be initialized before
productRepository
Click to expand...

Yes - C# does not specify the order so:

private int a = 123;
private int b = a;

gives this error.

Note that this is just a decision by the C# people.

The Java people made another decision and the code snippet
is in fact valid in Java, because Java specify that fields
are initialized in textual order.

Arne
 
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