Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 848
  • Last Modified:

Converting data types...

To convert a BSTR to char type, I was told to use:

// bstrTEXT comes in through function (e.g. function( BSTR bstrTEXT ))
char *charTEXT;
*charTEXT = ConvertBSTRToString(bstrTEXT);

But the compiler tells me this (am I using the right function to convert BSTR to char???):

error C2065: 'ConvertBSTRToString' : undeclared identifier

Also, when coding:

BSTR bstrSomething;
bstrSomething = "Some text...";

I get these errors during compile-time:

error C2015: too many characters in constant
error C2440: '=' : cannot convert from 'char [5]' to 'unsigned short *'

Thanks...
0
loyaliser
Asked:
loyaliser
  • 5
  • 5
1 Solution
 
stefanrCommented:
I think the function should be
void AFXAPI AfxBSTR2CString(CString* pStr, BSTR bstr);
in afxpriv2.h (VC++ 6.0 SP1)
To convert manually, use

BSTR bstr = SysAllocString("Some text");

The online help for SysAllocString says

BSTR SysAllocString(OLECHAR FAR* sz);

Allocates a new string and copies the passed string into it. Returns Null if there is insufficient memory, and if Null, Null is passed in.

Parameter
sz
A zero-terminated string to copy. The sz parameter must be a Unicode string in 32-bit applications, and an ANSI string in 16-bit applications.

Return Value
If successful, points to a BSTR containing the string. If insufficient memory exists or sz was Null, returns Null.

Comments
You can free strings created with SysAllocString using SysFreeString.

If you are using Unicode, then according to the help cited above you should write

BSTR bstr = SysAllocString(L"Some text");
0
 
stefanrCommented:
Sorry, I mean of course if you are using a 32-bit application, you should write L"Some text" as the SysAllocString parameter.
0
 
loyaliserAuthor Commented:
thanx...
0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 
loyaliserAuthor Commented:
What about converting from BSTR to char?? I am using:

*charTEXT = ConvertBSTRToString(bstrTEXT);

but the compiler says:

error C2065: 'ConvertBSTRToString' : undeclared identifier
0
 
stefanrCommented:
I think that the WideCharToMultiByte function is the one to use when converting from BSTR to char...
0
 
loyaliserAuthor Commented:
WideCharToMultiByte is not really working out for me... how do I concatenate a BSTR to a char [] data type:

char charData[50];
BSTR bstrData;

for example, strcat(charData, bstrData) - is there a similar function to strcat?

Thanks again...
0
 
stefanrCommented:
Wouldn't this work?

char szBstr[256] = { 0 };

if (0 == WideCharToMultiByte(CP_ACP, 0, bstrData, -1, szBstr, sizeof(szBstr), NULL, NULL))
{
   cerr << "Translation failed. Error Code "<< GetLastError() << endl;
}
else
{
   char szData[50] = { 0 };
   . . .
   strcat(szData, szBstr);
}

0
 
loyaliserAuthor Commented:
Yeah, that worked... thanks again!
0
 
loyaliserAuthor Commented:
I hope you don't mind, but what would be the code for doing it the other way around... char [] to BSTR?

Thanks...
0
 
stefanrCommented:
char szData[50] = { 0 };
   . . .
wchar_t lszData[50] = { 0 };
if (0 == MultiByteToWideChar(CP_ACP, 0, szData, -1, lszData, sizeof(lszData)/sizeof(wchar_t)))
{
   cerr << "Conversion to wide char string failed. Error Code " << GetLastError() << endl;
}
else
{
   BSTR bstrData = SysAllocString(lszData);
   if (NULL == bstrData)
   {
      cerr << "Conversion to BSTR string failed. Error Code " << GetLastError() << endl;

   }
   else
   {
      . . .
      SysFreeString(bstrData); // Don't forget to free the string when done with it.
      bstrData = NULL;
   }
}
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

  • 5
  • 5
Tackle projects and never again get stuck behind a technical roadblock.
Join Now