Question

I am probably just being thick but I cannot figure out what to do here….

I have a library I am trying to create that will have a virtual function that the user can use to create a custom error handler to call later in the code. One of the main hiccups I am hitting is that these errors will be stored in a collection for calling randomly.

Here’s some pseudo code

class Error
{
    string Error {get; set;}
    int ErrorCode {get; set;}

    public void ErrorFunction(params obj[] arrParams);
}


class program
{
    List<Error> errorlist = new List<Error>();

    static void Main(string[] args)
    {
         initList();
         errorlist[0].ErrorFunction("Sometext");         
    }

    public void initList()
    {

         Error err = new Error();
         err.ErrorFunction = MyOverloadedError;

         errorlist.add(err);
    }

    public void MyOverloadedError(params obj[] arrObjects)
    {
         Console.WriteLine(arrObjects); 
    }
}

I seem to remember being able to do this simply with a
void* and a call using the addressof for assigning the function to be called.

Like I said perhaps I am being thick, I know that I have to use a delegate, but I cannot figure out how to define a delegate where it exists in an instance of the class and not as a static member of the class.

to reiterate (since I am tired and not sure if I am making this clear or just more confusing) I want to make a member function that can have a custom function assigned to it.

so basically I can do the following

Error myError = new Error();
myError.ErrorFunction = SomeCustomFunction;
...
myError.ErrorFunction("Some Parameters"); //effectively calling some static function elsewhere

Thanks in advance! my brain hurts too much….

Answer 1

Not sure what you want to achieve or whether an event is more appropriate, but here’s your pseude-code, fixed up to be valid, working C# code:

delegate void ErrorDelegate(params object[] arrParams);
class Error
{
    string ErrorText { get; set; }
    int ErrorCode { get; set; }

    public ErrorDelegate ErrorFunction;
}

static class Program
{
    static List<Error> errorlist = new List<Error>();

    static void initList()
    {

        Error err = new Error();
        err.ErrorFunction = MyOverloadedError;

        errorlist.Add(err);
    }


    static void MyOverloadedError(params object[] arrObjects)
    {
        Console.WriteLine(arrObjects);
    }

    static void Main(string[] args)
    {
        initList();
        errorlist[0].ErrorFunction("Sometext");     
    }
}