Error occuring with DirectX program

[shrink_tubing]

Hi,

I've been trying to get a demo program for DirectX to run and I'm getting the following error log when compiling:

Code:

- cannot convert `const wchar_t[12]' to `const CHAR*' in assignment

Code:

- cannot convert `const wchar_t*' to `const CHAR*' for argument `2' to `HWND__* CreateWindowExA(DWORD, const CHAR*, const CHAR*, DWORD, int, int, int, int, HWND__*, HMENU__*, HINSTANCE__*, void*)'

The code defines a structure of type WNDCLASSEX with a variable name called 'wc'. When it hits the following line:

Code:

wc.lpszClassName = L"WindowClass";

It gets mad. I checked out online what the structure WNDCLASSEX has as its defined data members and it seems the variable lpszClassName requires a pointer to a classname which is terminated with a null character - which as I understand can be represented with '/0'. I don't think the null character is an issue though as if you look it is complaining that an array called wchar_t[12] cannot convert to what looks like a pointer to a constant variable of type char - but written in capitals for some reason. Given that there are 11 letters in the name "Windowclass" then it follows that the code must have implemented a null character automatically as the array size is 12 not 11.

I also thought an array variable was basically just read as a pointer by code too. So it seems to me that the data member of the structure WNDCLASSEX is being passed a pointer to a null terminated string, yet the program still complains.

Can anyone shed any light on this, is this an issue relating to a windows version which is out of date or something? Cheers!

[Brian]

It's \0...

However, when using things like CreateWindowEx, you NEED to use const char*! Literally, you need to make sure your string is a pointer.

If you have say, char b[20] = {"Some phrase"};
Then you need to make a pointer to it.
const char *pb = &b;
and then put it into the createwindowex.

Obviously some experimenting would be required.

[shrink_tubing]

Thanks Brian

[NicolasKohr]

I think reading a few tutorials on pointers would help you a lot in this area. Windows API can get confusing with all the pointers.

[rubix]

(02-06-2010 01:34 PM)Brian Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.It's \0...

However, when using things like CreateWindowEx, you NEED to use const char*! Literally, you need to make sure your string is a pointer.

If you have say, char b[20] = {"Some phrase"};
Then you need to make a pointer to it.
const char *pb = &b;
and then put it into the createwindowex.

Obviously some experimenting would be required.

That's not true. In this example, you can pass something like

Code:

char name[] = "test";

to the second or third parameter of CreateWindowEx fine.

@shrink_tubing

your getting the error because wc.lpszClassName is of the type LPCTSTR, your trying to assign it a wide character string. Instead of using

Code:

L"text"

instead try

Code:

TEXT("text");
or
_T("text");

TEXT() might be _TEXT(), cant remember.

Although this particular problem wasn't a pointer issue, if you do have problems understanding pointers it would be a good idea to take NicolasKohr's advice and read up on them. As you will most likely get into it them in DirectX programming.