Visual Studio 2008 SP1 (C#) IDE bug

Feel free to download the tiny project for the sample...

• Download Vcs2008Sp1_IdeBug - 28.85 KB

Introduction

Before all, this is my very first contribution (and it is NOT a classic application!) and I want to take advantage to thanks many of you that are helping so much the development. I will try hard to write down something useful in the near future, but at the moment I only drop this issue...

Today I have found a dirty bug in the Visual Studio 2008 Sp1 IDE or, at least, in the Visual C# Express since I am using it.

Using the code

The problem itself is tricky, because the (really useful) Intellisense tip showing the value of the variables, just fail on a simple inheritance case.

As you may see on the picture, there are two classes: let B inherited by C.

Now let assuming both B and C have the same property (signature), however with different access modifiers: let the base's property be marked as "virtual" and the derived's one marked as "override".

The "entire" program for test is just below:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            C c = new C();
            Console.WriteLine(c.Exec());
            Console.ReadKey();
        }
    }



    class B
    {
        public virtual int Value
        {
            get { return 10; }
        }
    }



    class C : B
    {
        public override int Value
        {
            get { return 5; }
        }


        public int Exec()
        {
            return base.Value; //this correctly returns 10
        }
    }
}
		

If you try to run the program, it outputs correctly "10" in the console window...but, what if you try to walk the code and stop just over the line marked with a remark?

Note: place a breakpoint here:

    ...

        public int Exec()
        {
            return base.Value; //place breakpoint here, then hover it
        }
   
    ...

Here is a simple snapshot of the behavior:

Trick!...the tip shows "5" not "10", as I were typed as:

    ...

        public int Exec()
        {
            return this.Value; //that MUST show 5!
        }
   
    ...

Points of Interest

I am assuming that Visual C# Express has the same "engine" of the bigger brother Visual Studio. I was not able to try this snippet inside the "real" Visual Studio Pro or superior. Please, feel free to feedback any different behavior.

History

First release.