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Convincing legacy application VB6 developers to make the switch to C#

I know this question could be similar to others but really I'm looking for reasons why VB6 developers should switch to C#.

My company recently approved project to be written in C#, so we have a lot of VB.Net programmers, however, we have some legacy app developers as well that are in VB6. We have a time frame to re-write those apps into .Net web apps. So no matter what they will have to learn new stuff.

One of the developers today specifically asked "why should we switch to C#?"

I responded that the community largely has decided that C# is the way to go with about 80% of the examples in C#. I am a VB.Net programmer and I am excited to finally cut my teeth on C#, however, being that I'm so new I'm not sure I can answer the "why?" question. My reasons are more because I want to learn it.

So without descending into a VB verses C# I really am curious if there are any resources that I can send to these developers to calm their nerves.

Looking forward to your input!

Has anyone had success with Visual Studio 6 on Windows 7?

VS6 popped off a series of errors before bombing out completely during install on Windows 7. I specifically need to get VB6 functioning on Windows 7. Anyone having any luck?

Escape double quote in VB string

I have used following piece of code to execute schtasks command from VB6. While executing it, ignores folder if they contains spaces. For example, "C:\program files\test\test.exe" will be converted to "c:\program ". How do I solve this issue?

MyAppname =  Chr(34) & App.Path & "\" & App.EXEName & ".exe" & Chr(34)
StrCommand = "schtasks /create /sc ONLOGON /RL HIGHEST  /tn myapp  /tr " & MyAppname  
Shell StrCommand, vbHide   

New task added as "c:\program" instead of "C:\program files\test\test.exe"

Thanks in advance.

What does the Call keyword do in VB6?

There's some code in our project that looks a bit like this:

Private Sub Method1()
    Call InnerMethod
End Sub

Private Sub Method2()
    InnerMethod
End Sub

Private Sub InnerMethod()
    '' stuff
End Sub

What's the advantage of doing Method1 over Method2?

A Simple C# DLL - how do I call it from Excel, Access, VBA, VB6?

I have a simple class library written in c#.

using System;
namespace TestDll
{
    public class Test
    {
        public string HelloWorld
        {
            get
            {
                return "Hello World";
            }
        }
    }
}

My question is how can I call this HelloWorld function from Microsoft Office Visual Basic (which I think is VB6)?

My first step was to add the DLL as a reference - but on browsing and selecting the compiled DLL the message "Can't add a reference to the specified file." was thrown.

Can anyone point me in the right direction as to why/how to get this working?

Thanks in advance SO!

Compile a DLL in C/C++, then call it from another program

I want to make a simple, simple DLL which exports one or two functions, then try to call it from another program... Everywhere I've looked so far, is for complicated matters, different ways of linking things together, weird problems that I haven't even begun to realize exist yet... I just want to get started, by doing something like so:

Make a DLL which exports some functions, like,

int add2(int num){
   return num + 2;
}

int mult(int num1, int num2){
   int product;
   product = num1 * num2;
   return product;
}

I'm compiling with MinGW, I'd like to do this in C, but if there's any real differences doing it in C++, I'd like to know those also. I want to know how to load that DLL into another C (and C++) program, and then call those functions from it. My goal here, after playing around with DLLs for a bit, is to make a VB front-end for C(++) code, by loading DLLs into visual basic (I have visual studio 6, I just want to make some forms and events for the objects on those forms, which call the DLL).

I need to know how to call gcc (/g++) to make it create a DLL, but also how to write (/generate) an exports file... and what I can/cannot do in a DLL (like, can I take arguments by pointer/reference from the VB front-end? Can the DLL call a theoretical function in the front-end? Or have a function take a "function pointer" (I don't even know if that's possible) from VB and call it?) I'm fairly certain I can't pass a variant to the DLL...but that's all I know really.

update again

Okay, I figured out how to compile it with gcc, to make the dll I ran

gcc -c -DBUILD_DLL dll.c
gcc -shared -o mydll.dll dll.o -Wl,--out-implib,libmessage.a

and then I had another program load it and test the functions, and it worked great, thanks so much for the advice, but I tried loading it with VB6, like this

Public Declare Function add2 Lib "C:\c\dll\mydll.dll" (num As Integer) As Integer

then I just called add2(text1.text) from a form, but it gave me a runtime error:

"Can't find DLL entry point add2 in C:\c\dll\mydll.dll"

this is the code I compiled for the DLL:

#ifdef BUILD_DLL
#define EXPORT __declspec(dllexport)
#else
#define EXPORT __declspec(dllimport)
#endif

EXPORT int __stdcall add2(int num){
  return num + 2;
}

EXPORT int __stdcall mul(int num1, int num2){
  return num1 * num2;
}

calling it from the C program like this worked, though:

#include<stdio.h>
#include<windows.h>

int main(){

  HANDLE ldll;
  int (*add2)(int);
  int (*mul)(int,int);

  ldll = LoadLibrary("mydll.dll");
  if(ldll>(void*)HINSTANCE_ERROR){
    add2 = GetProcAddress(ldll, "add2");
    mul = GetProcAddress(ldll, "mul");
    printf("add2(3): %d\nmul(4,5): %d", add2(3), mul(4,5));
  } else {
    printf("ERROR.");
  }

}

any ideas?

solved it

To solve the previous problem, I just had to compile it like so:

gcc -c -DBUILD_DLL dll.c
gcc -shared -o mydll.dll dll.o -Wl,--add-stdcall-alias

and use this API call in VB6

Public Declare Function add2 Lib "C:\c\dll\mydll" _
    (ByVal num As Integer) As Integer

I learned not to forget to specify ByVal or ByRef explicitly--I was just getting back the address of the argument I passed, it looked like, -3048.

Visual Basic 6.0 lives forever like Cobol [closed]

In the last 3-5 years I have been renewing an insurance application and a commmercial integration toolkit based on Visual Basic 6.0.

According to Microsoft's "It just works policy" the IDE is no longer supported after april 8th 2008.

It still works to develop and deploy Visual Basic 6.0 applications.

When will it be impossible to support Visual Basic 6.0 applications, or will they live forever like Cobol applications do?

Update: Microsoft statement march 2010: The Visual Basic team is committed to “It Just Works” compatibility for Visual Basic 6.0 applications on Windows Vista, Windows Server 2008 including R2, and Windows 7.

Update may 2011:
Happy 20th Birthday Visual Basic!

Implementing String.Format() in VB6

Can String.Format() be implemented in VB6, at least a close-enough version of it that could be useful when programming in good ol' VB6?

Good resource on the matter of VB6 string manipulation performance: http://www.aivosto.com/vbtips/stringopt2.html

On a related not, I also came up with a couple string comparison functions, find them here on CodeReview.SE

These functions are tremendously useful for improving VB6 readability, especially if you've been spoiled with .net code lately and suddenly are required to dive into a VB6 code base... Enjoy!

What is the difference between Dim, Global, Public, and Private as Modular Field Access Modifiers?

In VB6/VBA, you can declare module-level variables outside of a specific Sub or Function method. I've used Private and Public before inside modules and understand them like so:

• Public - visible to all code inside the module and all code outside the module, essentially making it global.
• Private - visible only to code inside the module.

I've noticed that you can use Dim and Global as modifiers for modular variables. Are Dim and Global different from Private and Public, respectively, when used as access modifiers on modular fields? If so, how are they different?

Is there a vb6 decompiler?

I lost the source code from one project I did on the company I'm working for and haven't been able to find a vb6 decompiler, does that even exists?

Forgot to say that I only have the EXE. I completely forgot about this project and rescued the EXE from a user's machine.

Is There a JSON Parser for VB6 / VBA?

I am trying to consume a web service in VB6. The service - which I control - currently can return a SOAP/XML message or JSON. I am having a really difficult time figuring out if VB6's SOAP type (version 1) can handle a returned object - as opposed to simple types like string, int, etc. So far I cannot figure out what I need to do to get VB6 to play with returned objects.

So I thought I might serialize the response in the web service as a JSON string. Does a JSON parser exist for VB6?

What is the difference between dim and set in vba

Pardon me as am a newbie in VBA, VB.NET.

Sometimes I use

Dim r as Range
r = Range("A1")

Other times I use

Set r = Range("A1")

What is the difference? And when should I use what?

Stop Visual Basic 6 from changing my casing

Very simple question that is apparently impossible to find a decent answer to: How can I make Visual Basic 6 stop changing my ^@#*ing variable casing!?!

I know that the general opinion of a great many VB users is that this "feature" is actually quite helpful, but I doubt that they use it much with any source control system. This is absolutely INFURIATING when you are trying to collaborate on a project of any significant size with several other developers. If ignored, you produce thousands of false-positive "changes" to your files (even ones with no actual code changes!) that pollute the revision history and make it near impossible in some cases to locate the actual change that took place.

If you don't ignore it (like my office, where we have been forced to implement a "no unneeded case change" policy), you spend 5x the time you would normally on each commit because you have to carefully revert out VB's "corrections" on every file, sometimes reverting hundreds of lines to put in a one line change.

Surely there must be a setting, plugin, hack, etc. out there that can remove this unwanted "feature"? I am willing to take any method I can get as long as it doesn't require me to pick through piles of phantom diffs. And to squash a couple of complaints up front: No, I can't turn off case detection in my diff tool, that's not the point. No, we can't just make the case changes globally. We're working with hundreds of thousands of LOC being worked on by multiple developers spanning many years of development. Synchronizing that is not feasible from a business standpoint. And, finally: No, we cannot upgrade to VB.net or port to another language (as much as I would love to).

(And yes, I am just a tiny bit peeved at the moment. Can you tell? My apologies, but this is costing me time and my company money, and I don't find that acceptable.)

Alternative IDE for VB6 and VBA [closed]

I've been spoiled by Visual studio 2008 and Eclipse and have to do a little maintainence work on a VB6 app.

Does anyone know of an alternative/ updated IDE for VB6?

A rewrite is not an option I'm just fixing a couple of bugs and it's a big codebase.

Equivalent VB keyword for 'break'

I just moved over to the Visual Basic team here at work.

What is the equivalent keyword to break in Visual Basic, that is, to exit a loop early but not the method?