Thread: Data type error when converting an old WinAPI C++ code as a new VS 2022 C++ project

Hi all.

I'm trying to write this code from an old WinAPI C++ book (code snippet Image at the bottom) into a new C++ project. What it does is create a clone process. But when i code it into VS 2022, I get the error:

Code:

"Argument of type "TCHAR *" is incompatible with parameter of type "char *" "

at line-17 (sprintf, 1st arg, below code). What's causing this please? And how to fix it?



VS 2022



VC 6.0

A couple of things.

1. In modern C++, you should use this in place of include <stdio.h>
#include <cstdio>

2. When dealing with anything TCHAR, you need to be aware of the "Generic-Text Routine Mappings"
_scprintf, _scprintf_l, _scwprintf, _scwprintf_l | Microsoft Learn

Back in VC6 days, TCHAR was just char, so it was easy to be lazy and use the ISO standard name for the function.

Originally Posted by Salem

A couple of things.

1. In modern C++, you should use this in place of include <stdio.h>
#include <cstdio>

2. When dealing with anything TCHAR, you need to be aware of the "Generic-Text Routine Mappings"
_scprintf, _scprintf_l, _scwprintf, _scwprintf_l | Microsoft Learn

Back in VC6 days, TCHAR was just char, so it was easy to be lazy and use the ISO standard name for the function.

Thanks that helped. Sorry, been with C# for last the decade, I lost my touch with C++. Thought to relearn.

Anyways, when I did this, i got the error:

Code:

const variable "szCommandLine" requires an initializer

Code:

const char szCommandLine[MAX_PATH];
 _scprintf(szCommandLine, "\"%s\" %d", szfilename, nCloneID);

And by the way, where can I find out how to properly call the old API functions (back in VC6 days) now in VS 2022? Maybe kinda like a guide for people who're returning to C++?, if there's such a thing.

Thanks

Why would you be declaring it const, if you intend to modify it with the sprintf?

Originally Posted by Salem

Why would you be declaring it const, if you intend to modify it with the sprintf?

My mistake!