TCHAR to char *

[Mark Salsbery]

Rajesh_Parameswaran wrote:

buff = strTemp.GetBuffer(strTemp.GetLength());

You can't convert a TCHAR* to a TCHAR[512] so that assignment won't work. What are you trying to do?  Do you need to convert the contents of the TCHAR array to an array of char or just cast the pointer to the array to a different type? Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Mark Salsbery]

I didn't notice your tempBuff variable, so I assume you want something like this:

TCHAR buff[512]={NULL};
   char tempBuff[512]={NULL};

_stprintf(buff, _T("Hello World"));

strcpy(tempBuff, CT2CA(buff));

Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Michael Dunn]

Use an ATL conversion macro:

CString s = _T("Hello world!");
const char* p = T2CA(LPCTSTR(s));

More here[^] and here[^]

--Mike-- Visual C++ MVP :cool: LINKS~! Ericahist | PimpFish | CP SearchBar v3.0 | C++ Forum FAQ Hungarian notation FTW

[Mark Salsbery]

Mike, That doesn't work on VS 2005 which is why I coded my example like I did (besides trying to fit the OP's code).  How does one force the macros to work old-style like you've shown? Thanks, Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Michael Dunn]

What about it doesn't work in VC8? Does CT2CA work instead?

--Mike-- Visual C++ MVP :cool: LINKS~! Ericahist | PimpFish | CP SearchBar v3.0 | C++ Forum FAQ Hungarian notation FTW

[Mark Salsbery]

Note this is just for me, in one test application - MFC/Unicode/VS2005.  I ask because I don't know :) T2CA doesn't compile. CT2CA works like this

char buff[80];
   strcpy(buff, CT2CA(_T("Hello World")));

but doesn't work like this

CString s = _T("Hello world!");
   const char* p = CT2CA(LPCTSTR(s));
   // p is invalid here

Here's a sample from  ATL and MFC String Conversion Macros[^]

// Example 3
// Incorrect use of conversion macros.

void ExampleFunctionW( LPCWSTR pszW )

{
 // Create a temporary instance of CW2A,

// save a pointer to it and then delete
 // the temportary instance.

LPCSTR pszA = CW2A( pszW );
 // The pszA in the following line is an invalid pointer,
 // as the instance of CW2A has gone out of scope.
 ExampleFunctionA( pszA );

}

In the section "A Warning Regarding Temporary Class Instances" there's more details. I just don't know how to use the old ones, which it states are still supported.  I'm missing some detail somewhere :) Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Mark Salsbery]

I found it - need a macro.

USES_CONVERSION;
CString s = _T("Hello world!");
const char* p = T2CA(LPCTSTR(s));
// p is ok to use until the end of the function! Yay!

That's better :) To recap:

USES_CONVERSION;
CString s = _T("Hello world!");
const char* p1 = CT2CA(LPCTSTR(s));
// p1 BAD!
const char* p2 = T2CA(LPCTSTR(s));
// p2 GOOD!

Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Rajesh_Parameswaran]

Hi Mark/Micheal, Thanks for the response. I'm still having problem in using the macro USES_CONVERSION. I'm not using ATL in my project. Could you let me know an alternative solution with VC++6.0 / MFC? thanks in advance, Rajesh

[Mark Salsbery]

Hi Rajesh, Michael's solution should work for VC++ 6.  It will NOT work on VC++ 8, so you may want to keep that in mind if you ever plan to migrate to a new version of C++. *EDIT* Actually, it WILL work, but you'll need to add the USES_CONVERSION macro in VC++ 8. Sorry for my confusion :) Mark

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Last modified: 1hr 10mins after originally posted --

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Obukhov]

I found the code on [http://www.wincli.com/?p=72]. These two functions is what you need: // returns number of TCHARs in string int wstrlen(_TCHAR * wstr) { int l_idx = 0; while (((char*)wstr)[l_idx]!=0) l_idx+=2; return l_idx; } // Allocate char string and copy TCHAR->char->string // Don't forget to release the allocated memory!!! char * wstrdup(_TCHAR * wSrc) { int l_idx=0; int l_len = wstrlen(wSrc); char * l_nstr = (char*)malloc(l_len); if (l_nstr) { do { l_nstr[l_idx] = (char)wSrc[l_idx]; l_idx++; } while ((char)wSrc[l_idx]!=0); } nstr[l_idx] = 0; return l_nstr; }