Accessibility of the Generic List

Hi Alan,

You are totally 100% right! I did not read the error message carefully enough.

You were corrent in assuming that the Client class is not a form. And it is the type which I used with the generic list. And it defaulted to internal. Therefore, the list had that inherent  restriction.

Thanks very much for helping me get on top of that. It was bugging me. I have now made the Client class public and changed the Report form's constructor back to public. Works fine.

Ace!!!

Hi Dave,

It's the Client class (which I didn't think would be a form) that I thought might be internal. In other words, your set up would be something like this:

namespace CustomerWeightTracker
{
   public partial class Report : Form
   {
       public Report(List clients)
       {
          //.....
       }

       //.....
   }

   class Client // not declared public so internal by default
   {
       //.....
   }
}

Although the generic List class itself is public, its 'effective' accessibility is that of its type argument. So if the type argument is internal then so too is the List.

However, a public constructor or method must have parameters which are themselves public, otherwise it would not be possible to call it from outside the assembly in which it is declared.

To be honest, I can't think of any other possible explanation here.

Hi Alan,

All forms that I create default to public e.g. public partial class Report : Form

The main form frmMain in the app is public. It definitely has something to do with the generic datatype. All other datatypes (that I have tested) do not have this issue.

Cheers

My guess is that the CustomerWeightTracker.Client class is internal which is the default accessibility for classes.

Consequently, the compiler is complaining because you're using an internal type parameter to specify the parameter type of a public constructor.

If I'm right about this, then making the CustomerWeightTracker.Client class public would also have solved the problem.