TCHAR issue

goldenrose9

In Win32 C++ how to convert

TCHAR* to LPCTSTR
TCHAR to LPTSTR

Please help...:confused::confused:

gold

jk chan

use MultiByteToWideChar and WideCharToMultiByte functions. see http://msdn.microsoft.com/en-us/library/dd319072(v=vs.85).aspx[^] or you can use mbstowcs etc functions.You need to set locale before using it( setlocale ) see http://msdn.microsoft.com/en-in/library/k1f9b8cy(v=vs.80).aspx[^] I hopes you know what a TCHAR is. if you application type is multibyte TCHAR is char , otherwise wchar_t

If u can Dream... U can do it

Lost User

What do you mean by convert? TCHAR* is merely a pointer to a char or wchar_t depending on the definition of UNICODE. LPCTSTR is a typedef to const TCHAR* so no conversion is necessary; but you may need a cast to satisfy the compiler. TCHAR is a single character so cannot be converted or cast to LPTSTR; if you actually meant TCHAR* then both expressions evaluate to the same thing: a pointer to a character or wide character.

Just say 'NO' to evaluated arguments for diadic functions! Ash

goldenrose9

Thanx, my one doubt is cleared, about TCHAR to LPTSTR My Program deals with UNICODE only a small example will very helpfull for me, of how to convert TCHAR* to LPCTSTR and LPTSTR. Thanx in advance.

gold

Roger Broomfield

TCHAR* to LPCTSTR is a simple typecast

TCHAR* pch;
LPCTSTR pcch = (LPCTSTR)pch;

TCHAR to LPTSTR is an address of operator

TCHAR ch;
LPTSTR pch = &ch;

Lost User

goldenrose9 wrote:

a small example will very helpfull for me, of how to convert TCHAR* to LPCTSTR and LPTSTR.

There is no conversion involved; as I said in my previous post TCHAR* and LPTSTR equate to the same thing, a pointer to a string (character array). LPCTSTR is the same as const TCHAR*, a pointer to a string constant.

Just say 'NO' to evaluated arguments for diadic functions! Ash

goldenrose9

LPTSTR __stdcall gHelp(TCHAR value)
{
LPTSTR pch;
pch = &value;
return pch;
}

compiler gives warning
warning C4090: 'return' : different 'const' qualifiers

gold

Cedric Moonen

Here[^] is an excellent article explaining everything you need to understand C++ strings.

Cédric Moonen Software developer
Charting control [v3.0] OpenGL game tutorial in C++

Lost User

You will also have a problem that you are returning a TCHAR* to a TCHAR value, not an array (i.e. string). Do not do this or you will end up with memory overwrites and/or invalid data. As to your compiler warning, you must have a definition of gHelp which reads something like:

LPCTSTR __stdcall gHelp(TCHAR value);

Just say 'NO' to evaluated arguments for diadic functions! Ash

Rajesh R Subramanian

goldenrose9 wrote:

TCHAR* to LPCTSTR

Usually, no conversion needed. If a function is promising you that it won't modify the contents (thereby expecting an LPCTSTR), you can still pass on a normal TCHAR* to it.

goldenrose9 wrote:

TCHAR to LPTSTR

That makes absolutely no sense. TCHAR is a character (wide or not depends on the build), and LPTSTR is a pointer to one such character. How can you convert one to another?!

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

goldenrose9

thanx a lot.

gold

Stefan_Lang

This won't work. You are passing the TCHAR variable by value, so the parameter value is just a temporary local copy, and the address of it will be invalidated upon return! Pass the TCHAR parameter by reference instead, like this:

LPTSTR __stdcall gHelp(TCHAR& value)
...