How does one convert LPTSTR to LPCTSTR? - c++

Question

I need to convert:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms646839(v=vs.85).aspx
lpstrFileTitle
Type: LPTSTR
The file name and extension (without path information) of the selected file. This member can be NULL.
Even though in MSVC++ 2012 Express it says its LPSTR.
To
http://msdn.microsoft.com/en-us/library/windows/desktop/bb172802(v=vs.85).aspx
pSrcFile [in]
Type: LPCTSTR
Pointer to a string that specifies the filename. If the compiler settings require Unicode, the data type LPCTSTR resolves to LPCWSTR. Otherwise, the string data type resolves to LPCSTR. See Remarks.
I would very much appreciate this. :)
char szFileName[MAX_PATH] = {0};
char szFileTitleName[MAX_PATH] = {0};
HRESULT hr = S_OK;
RtlZeroMemory(&gc.ofn, sizeof(gc.ofn));
gc.ofn.lStructSize = sizeof(gc.ofn);
gc.ofn.hwndOwner = hWnd;
gc.ofn.lpstrFilter = "All Image Files\0" "*.bmp;*.dib;*.wdp;*.mdp;*.hdp;*.gif;*.png;*.jpg;*.jpeg;*.tif;*.ico\0"
"Windows Bitmap\0" "*.bmp;*.dib\0"
"High Definition Photo\0" "*.wdp;*.mdp;*.hdp\0"
"Graphics Interchange Format\0" "*.gif\0"
"Portable Network Graphics\0" "*.png\0"
"JPEG File Interchange Format\0" "*.jpg;*.jpeg\0"
"Tiff File\0" "*.tif\0"
"Icon\0" "*.ico\0"
"All Files\0" "*.*\0"
"\0";
gc.ofn.nMaxFileTitle = MAX_PATH;
gc.ofn.lpstrFileTitle = gc.szFileTitleName; // its a char
gc.ofn.lpstrFile = szFileName;
gc.ofn.nMaxFile = MAX_PATH;
gc.ofn.lpstrTitle = "Open Image";
gc.ofn.Flags = OFN_FILEMUSTEXIST | OFN_PATHMUSTEXIST;
if(GetOpenFileName(&gc.ofn)) {
gc.render_on = true;
}
.
D3DXCreateTextureFromFileEx (d3dDevice, gc.szFileTitleName , D3DX_DEFAULT_NONPOW2, D3DX_DEFAULT_NONPOW2, 0, 0,
D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, D3DX_DEFAULT, D3DX_DEFAULT,
colorkey, &init_map->image_info, NULL, &init_map->texture_buffer)
This will have a blank image. I have tested this with a messagebox right after GetOpenFile, and it returns great.
MessageBoxA ( NULL , gc.ofn.lpstrFileTitle , "" , 0 );
But before the D3DXCreateTextureFromFileEx, its messed up.
Just storing the the char into gc.szFileTitleName. No idea why the other way was going out of scope ...

Answer 1

LPCTSTR is just a const version of LPTSTR. That type of conversion is a standard conversion, so you shouldn't need to do anything explicitly to get what you want. Your error must be somewhere else.
Unless you are somehow compiling a piece of your code with UNICODE set and some without it...

Answer 2

GetOpenFileName(), D3DXCreateTextureFromFileEx(), and MessageBox() all deal with TCHAR-based strings, but you are not actually utilizing TCHAR in your code. Try this instead:
TCHAR szFileName[MAX_PATH] = {0};
TCHAR szFileTitleName[MAX_PATH] = {0};
HRESULT hr = S_OK;
RtlZeroMemory(&gc.ofn, sizeof(gc.ofn));
gc.ofn.lStructSize = sizeof(gc.ofn);
gc.ofn.hwndOwner = hWnd;
gc.ofn.lpstrFilter = TEXT("All Image Files\0") TEXT("*.bmp;*.dib;*.wdp;*.mdp;*.hdp;*.gif;*.png;*.jpg;*.jpeg;*.tif;*.ico\0")
TEXT("Windows Bitmap\0") TEXT("*.bmp;*.dib\0")
TEXT("High Definition Photo\0") TEXT("*.wdp;*.mdp;*.hdp\0")
TEXT("Graphics Interchange Format\0") TEXT("*.gif\0")
TEXT("Portable Network Graphics\0") TEXT("*.png\0")
TEXT("JPEG File Interchange Format\0") TEXT("*.jpg;*.jpeg\0")
TEXT("Tiff File\0") TEXT("*.tif\0")
TEXT("Icon\0") TEXT("*.ico\0")
TEXT("All Files\0") TEXT("*.*\0")
TEXT("\0");
gc.ofn.nMaxFileTitle = MAX_PATH;
gc.ofn.lpstrFileTitle = gc.szFileTitleName;
gc.ofn.lpstrFile = szFileName;
gc.ofn.nMaxFile = MAX_PATH;
gc.ofn.lpstrTitle = TEXT("Open Image");
gc.ofn.Flags = OFN_FILEMUSTEXIST | OFN_PATHMUSTEXIST;
if(GetOpenFileName(&gc.ofn)) {
gc.render_on = true;
}
.
D3DXCreateTextureFromFileEx (d3dDevice, gc.szFileTitleName , D3DX_DEFAULT_NONPOW2, D3DX_DEFAULT_NONPOW2, 0, 0, D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, D3DX_DEFAULT, D3DX_DEFAULT, colorkey, &init_map->image_info, NULL, &init_map->texture_buffer)
.
MessageBox(NULL, gc.ofn.lpstrFileTitle, TEXT(""), 0);