conversion to _bstr_t - newbie

Sarath C

_bstr_t is a type which can hold unicode string. CString strText; // format the value to CString strText.Format("%d",nValue); call strText.AllocSysString(); to convert SaRath.
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ThatsAlok

antonaras wrote:

integers and doubles to _bstr_t;

//Integer TCHAR szStr[100]; wsprintf(szStr,"%d",100); _bstr_t bstText(szStr); //Float TCHAR szStr[100]; wsprintf(szStr,"%f",100.10); _bstr_t bstText(szStr);

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Sarath C

ThatsAlok wrote:

TCHAR szStr[100]; wsprintf(szStr,"%d",100);

I think type defined by TCHAR has dependency to the current build environement(unicode/ MBCS). The compiler will define char array instead of unicode character array (wchar_t)in an MBCS environment. so there is a chance for error. I think, when it is better to declare wchar_t array instead of declaring TCHAR array since we are using wsprintf for formatting. what do u think? SaRath.
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antonaras

Thanks ThatsAlok I'm getting there is almost working how about doubles? Appreciate the help

ThatsAlok

SaRath C wrote:

I think type defined by TCHAR has dependency to the current build environement(unicode/ MBCS). The compiler will define char array instead of unicode character array (wchar_t)in an MBCS environment. so there is a chance for error.

Actually TCHAR is defined as :-

#ifdef UNICODE
#define TCHAR wchar_t
#else
#define TCHAR char
#endif

so you can use in both Character set. plus little mistake from my side too, wsprintf should be written something like this to make it character set independent

wsprintf(szChar,_T("%d"),100);

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ThatsAlok

SaRath C wrote:

_bstr_t is a type which can hold unicode string.

you getting very fast :)

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Sarath C

You will get the expected string depends on the format specifier you are specifying http://msdn2.microsoft.com/en-us/library/75w45ekt.aspx[^] SaRath.
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ThatsAlok

antonaras wrote:

how about doubles?

use %e format

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

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ThatsAlok

SaRath C wrote:

call strText.AllocSysString(); to convert

there can Memory Leak problem here!

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antonaras

Hey ThatsAlok i tried your code and it works fine with integers but i have double valField4; TCHAR szStr2[100]; wsprintf(szStr2,"%e",valField4); _bstr_t bstText2(szStr2); printf("%s\n",(LPCSTR)bstText2); the otput for bstText2 that i get is e why does that happen thanks again

Viorel

If you are familiar with STL, you can use one more method:

int i = 1234567;
double d = 123.4567;
_bstr_t s1, s2;

// convert integer
{
    std::ostrstream os;
    os << i << std::ends;
    s1 = os.str();
}
// convert double
{
    std::ostrstream os;
    os << d << std::ends;
    s2 = os.str();
}

antonaras

Thanks Viorel i tried your code but i get lots of compilation errors 'ostrstream' : undeclared identifier syntax error : missing ';' before identifier 'os' 'os' : undeclared identifier and so on what i'm doing wrong i have included string is there anything else i need to include thanks

Viorel

In order to use these STL features, you have to include a header file:

#include <strstream>

Next, you may receive an "unresolved external symbol" error displayed by the linker. In this case, you have to make one more addition: specify "comsuppwd.lib" in the "Linker --> Input --> Additional Dependencies" configuration option of your project. (In release compilation mode, specify "comsuppw.lib"). You can always see which header file or library is required by analyzing the descriptions in MSDN.

antonaras

thanks Viorel is working fine now thanks for all the help

David Crow

antonaras wrote:

can i convert integers and doubles to _bstr_t;

Just assign them:

double d;
int x;
_bstr_t str;
str = d;
str = (long) x;

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