I've tried everything I can think of, but it still comes back with following error:

Error 1 An object reference is required for the non-static field, method, or property 'MortimerPhonesEmployees.TestHarness.employees' C:\Users\Tom Magaro\Documents\Visual Studio 2008\Projects\Collections\MortimerPhonesEmployees\ TestHarness.cs 47 29 MortimerPhonesEmployees.

Here is the code. I've bolded and underlined the problem field.

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace MortimerPhonesEmployees
{
classTestHarness
{
Hashtable employees = newHashtable(31);
publicstaticvoid Run()
{
EmployeeID idMortimer = newEmployeeID("B001");
EmployeeData mortimer = newEmployeeData(idMortimer, "Mortimer",
100000.00M);
EmployeeID idArabel = newEmployeeID("W234");
EmployeeData arabel = newEmployeeData(idArabel, "Arabel Jones",
10000.00M);
while (true)
{
try
{
Console.Write("Enter employee ID (format:A999, X to exit)>");
string userinput = Console.ReadLine();
userinput = userinput.ToUpper();
if (userinput == "X")
return;
EmployeeID id = newEmployeeID(userinput);
DisplayData(id);
}
catch (Exception e)
{
Console.WriteLine("Exception occurred. Did you use the correct" +
"format for the employee ID?");
Console.WriteLine(e.Message);
Console.WriteLine();
}
Console.WriteLine();
}
}
privatestaticvoid DisplayData(EmployeeID id)
{
object empobj = employees[id];
if (empobj != null)
{
EmployeeData employee = (EmployeeData)empobj;
Console.WriteLine("Employee: " + employee.ToString());
}
else
Console.WriteLine("Employee not found: ID = " + id);
}
}
}

I am running on vs2008 but I can't afford the book for it.


any help would be appreciated.

Thanx,

Tom

__________________
Thomas G Magaro

The 'employees' field isn't initialized because you aren't constructing an instance of the 'TestHarness' type.

1. Either make 'employees' a static field (the CLR will allocate memory for the field when the type is loaded), or

2. Make your Run() and DisplayData() methods instance methods:

public void Run()
private void DisplayData(EmployeeID id)

and construct an instance of 'TestHarness', leaving 'employess' declared as an instance field (the CLR will allocate memory for the non-static field when it allocates an instance of the type).

TestHarness th = new TestHarness();
th.Run();

If you don't explicitly declare a constructor for 'TestHarness', the compiler will emit a public, parameterless constructor for you.

Sort of like:

// Field
Hashtable employees;

// .ctor
public TestHarness()
{
// Field initialization;
this.employees = new Hashtable(31);
}

You can leave the Run() and DisplayData() methods as static methods, but then they would require a parameter of type 'TestHarness' so you could pass them a 'TestHarness' instance, then do the field access through the 'TestHarness' instance variable.

TestHarness.Run(new TestHarness());
...
public static void Run(TestHarness th)
{
...
TestHarness.DisplayData(th, id);
...
}
...
public static void DisplayData(TestHarness th, EmployeeID id)
{
object empobj = th.employees[id];
if (empobj != null)
{...}
}

Pretty ugly...

P.S.

object empobj = employees[id];
if (empobj != null)

will always evaluate to null given what you have so far.

Anyway, easiest solution:

staticHashtable employees = newHashtable(31);

Hi Bob,

I'm kind of embarassed that it was that simple. I'll get the hang of it one of these days!

I appreciate that rapid response.


Thanks alot,

Tom

__________________
Thomas G Magaro