Convert CString to const char*

Question

How do I convert from CString to const char* in my Unicode MFC application?

Answer 1

Generic Conversion Macros (TN059 Other Considerations section is important):

A2CW     (LPCSTR)  -> (LPCWSTR)  
A2W      (LPCSTR)  -> (LPWSTR)  
W2CA     (LPCWSTR) -> (LPCSTR)  
W2A      (LPCWSTR) -> (LPSTR) 

• TN059: Using MFC MBCS/Unicode Conversion Macros

Answer 2

I recommendo to you use TtoC from ConvUnicode.h

const CString word= "hello";
const char* myFile = TtoC(path.GetString());

It is a macro to do conversions per Unicode

Answer 3

I had a similar problem. I had a char* buffer with the .so name in it.
I could not convert the char* variable to LPCTSTR. Here's how I got around it...

char *fNam;
...
LPCSTR nam = fNam;
dll = LoadLibraryA(nam);

Answer 4

Note: This answer predates the Unicode requirement; see the comments.

Just cast it:

CString s;
const TCHAR* x = (LPCTSTR) s;

It works because CString has a cast operator to do exactly this.

Using TCHAR makes your code Unicode-independent; if you're not concerned about Unicode you can simply use char instead of TCHAR.

Answer 5

If your CString is Unicode, you'll need to do a conversion to multi-byte characters. Fortunately there is a version of CString which will do this automatically.

CString unicodestr = _T("Testing");
CStringA charstr(unicodestr);
DoMyStuff((const char *) charstr);

Answer 6

To convert a TCHAR CString to ASCII, use the CT2A macro - this will also allow you to convert the string to UTF8 (or any other Windows code page):

// Convert using the local code page
CString str(_T("Hello, world!"));
CT2A ascii(str);
TRACE(_T("ASCII: %S\n"), ascii.m_psz);

// Convert to UTF8
CString str(_T("Some Unicode goodness"));
CT2A ascii(str, CP_UTF8);
TRACE(_T("UTF8: %S\n"), ascii.m_psz);

// Convert to Thai code page
CString str(_T("Some Thai text"));
CT2A ascii(str, 874);
TRACE(_T("Thai: %S\n"), ascii.m_psz);

There is also a macro to convert from ASCII -> Unicode (CA2T) and you can use these in ATL/WTL apps as long as you have VS2003 or greater.

See the MSDN for more info.