怎样将BSTR字符串转换为char数组

[new_red]

我在编写一个COM组件，组件内的方法原型如下：
STDMETHODIMP CFileTrans::UploadFile(BSTR FileIdentifier,int *result);
我想使用char数组作为文件名打开一个文件，使用TCP流套接字实施文件传输。请问：怎样将BSTR字符串转换为char数组？

[nbk16]

STDMETHODIMP CFileTrans::UploadFile(BSTR FileIdentifier,int *result);

char cFileId[MAX_LEN];

wcstombs(cFileId, FileIdentifier, sizeof(cFileId))

[ciml]

用W2A这个宏也可以

[名牌大灰狼]

COPY BSTR dat; char str[10] = "sdjfdf";dat = (BSTR)str;

[chaiyun]

如何将char*的串给BSTR？

[落入凡间的猪]

USES_CONVERSION;
char tBuff[100];
ZeroMemory(tBuff,100);
lstrcpy(tBuff,W2A(FileIdentifier));

[lixiaosan]

(3) BSTR转换成char*

　　方法一，使用ConvertBSTRToString。例如：

#include
#pragma comment(lib, "comsupp.lib")
int _tmain(int argc, _TCHAR* argv[]){
BSTR bstrText = ::SysAllocString(L"Test");
char* lpszText2 = _com_util::ConvertBSTRToString(bstrText);
SysFreeString(bstrText); // 用完释放
delete[] lpszText2;
return 0;
}

[lixiaosan]

方法二，使用_bstr_t的赋值运算符重载。例如：

_bstr_t b = bstrText;
char* lpszText2 = b;

[快乐鹦鹉]

BSTR bst;
char ch[10] = "sdjfdf";
bst = (BSTR)ch;
我刚才测试了一下，通过内存查看，bst的内容是"sdjfdf"，你不妨这样试一下。

[wangweixing2000]

下面是最安全的！为了你的项目没有漏洞!
//------------------------//
// Convert char * to BSTR //转换后的BSTR用完后通过::SysFreeString();删除
//------------------------//
inline BSTR ConvertStringToBSTR(const char* pSrc)
{
if(!pSrc) return NULL;

DWORD cwch;

BSTR wsOut(NULL);

if(cwch = ::MultiByteToWideChar(CP_ACP, 0, pSrc,
-1, NULL, 0))//get size minus NULL terminator
{
cwch--;
wsOut = ::SysAllocStringLen(NULL, cwch);

if(wsOut)
{
if(!::MultiByteToWideChar(CP_ACP,
0, pSrc, -1, wsOut, cwch))
{
if(ERROR_INSUFFICIENT_BUFFER == ::GetLastError())
return wsOut;
::SysFreeString(wsOut);//must clean up
wsOut = NULL;
}
}

};

return wsOut;
};

//------------------------//
// Convert BSTR to char * //转换后的char*用完后通过delete []删除
//------------------------//
inline char* ConvertBSTRToString(BSTR pSrc)
{
if(!pSrc) return NULL;

//convert even embeded NULL
DWORD cb,cwch = ::SysStringLen(pSrc);

char *szOut = NULL;

if(cb = ::WideCharToMultiByte(CP_ACP, 0,
pSrc, cwch + 1, NULL, 0, 0, 0))
{
szOut = new char[cb];
if(szOut)
{
szOut[cb - 1] = '\0';

if(!::WideCharToMultiByte(CP_ACP, 0,
pSrc, cwch + 1, szOut, cb, 0, 0))
{
delete []szOut;//clean up if failed;
szOut = NULL;
}
}
}

return szOut;
};


inline HRESULT BstrToString( const BSTR pString, char *pBuf, DWORD dwBufSize )
{
if ( NULL == pString )
{
return S_FALSE;
}
UINT nLen = SysStringLen( pString );
memset( pBuf, 0, dwBufSize );
if ( 0 == nLen )
{
return S_OK;
}
nLen *= sizeof( BSTR[1] );
if ( 0 == WideCharToMultiByte( CP_ACP, 0, pString,
nLen, pBuf, dwBufSize, NULL, NULL ) )
{
return S_FALSE;
}
return TRUE;
}

[FreeSeagull]

#include <stdio.h>
#include <stdlib.h>

void main( void )
{
int i;
char *pmbbuf = (char *)malloc( MB_CUR_MAX );
wchar_t *pwchello = L"Hello, world.";

printf( "Convert wide-character string:\n" );
i = wcstombs( pmbbuf, pwchello, MB_CUR_MAX );
printf( "\tCharacters converted: %u\n", i );
printf( "\tMultibyte character: %s\n\n", pmbbuf );
}

[FreeSeagull]

#include <stdlib.h>
#include <stdio.h>

void main( void )
{
int i;
char *pmbnull = NULL;
char *pmbhello = (char *)malloc( MB_CUR_MAX );
wchar_t *pwchello = L"Hi";
wchar_t *pwc = (wchar_t *)malloc( sizeof( wchar_t ));

printf( "Convert to multibyte string:\n" );
i = wcstombs( pmbhello, pwchello, MB_CUR_MAX );
printf( "\tCharacters converted: %u\n", i );
printf( "\tHex value of first" );
printf( " multibyte character: %#.4x\n\n", pmbhello );

printf( "Convert back to wide-character string:\n" );
i = mbstowcs( pwc, pmbhello, MB_CUR_MAX );
printf( "\tCharacters converted: %u\n", i );
printf( "\tHex value of first" );
printf( " wide character: %#.4x\n\n", pwc );
}

[enlith]

同意
wangweixing2000(星(准备跳槽中!!))
的做法

[adam]

CComBSTR、_bstr_t是对BSTR的封装,BSTR是指向字符串的32位指针。
char *转换到BSTR可以这样: BSTR b=_com_util::ConvertStringToBSTR("数据");///使用前需要加上头文件comutil.h
反之可以使用char *p=_com_util::ConvertBSTRToString(b);