How to convert double to BSTR

Question

2.00/5 (1 vote)

See more:

C++

Want to assign a double value to BSTR string.
Are there any macros /functions for this

Posted 25-Aug-11 23:44pm

explorerC

Add a Solution

4 solutions

Solution 4

1、use _gcvt to convert double to char*
2、(BSTR)(CString)your char* var

Posted 30-Aug-11 17:28pm

buyong

Comments

Member 12726815 8-Mar-18 18:32pm

is curious the sample code in solution 1.

prints me a memory address, example:
I add a cout << myvarbstr << end;

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Espen Harlinn · Accepted Answer · 2011-08-30T12:45:00

Solution 3

Why not use VarBstrFromR8[^] Windows API?

There are many other Data Type Conversion Functions[^] provided with Windows too.

Best regards
Espen Harlinn

Posted 30-Aug-11 12:45pm

Espen Harlinn

Comments

Sergey Alexandrovich Kryukov 6-Sep-11 20:03pm

My 5.
--SA

Espen Harlinn 7-Sep-11 4:49am

Thanks Sergey!

xuragan · Accepted Answer · 2011-08-30T12:01:00

C++

#include "windows.h"
#include "comutil.h"

void your_func(BSTR bstr);

int main()
{
   _bstr_t str(_variant_t(double(123.456)));
   
   // str is castable to BSTR
   // use it like this

   your_func(str);

   // or simply
   your_func(_bstr_t(_variant_t(double(123.456))));
   
   return 0;
}

CPallini · Accepted Answer · 2011-08-26T00:04:00

You may just represent a double value with a BSTR, for instance

C++

#include <windows.h>
#include <tchar.h>
#include <sstream>
using namespace std;

int main()
{
  wostringstream wos;
  double d = 0.57;
  wos << d;
  BSTR bstr = SysAllocString(wos.str().c_str());
  // enjoy with bstr
  // ...
  SysFreeString(bstr);
}

How to convert double to BSTR

4 solutions

Solution 4

Solution 3

Solution 2

Solution 1

Add your solution here

Preview 0