Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Can you pass a va_list as arguments to fill a CString (variable argument list)?

Posted on 1997-05-29
1
Medium Priority
?
1,176 Views
Last Modified: 2013-12-03
I have a class member that accepts a string with formatting capability, and therefore can have multiple arguments to fill the format sections. Can I simply take the string I get and the argument list and send it to CString and let it do the work of stuffing? How can I do this. I want to take the formatted string and send it to an open I/O stream. I'm using MSVC++ 4.2 under Win95 and WinNT 4.x. (Must I just add my own function like the protected CString::FormatV)?)

Here's my function member:
/////////////////////////////////////////////////////////////////////////////////////////////////
// this function member will extract the arguments into a va_list, set the new string, and
// append the string to the open report file
// it will display an error if a file has not been opened first with OpenReportFile
// this function will allow the passing of arguments as used in the printf and
// CString::Format functions (see Microsoft VC++ help for information on formatting codes)
//
// Input Variables:  lpszformatstr - string of text to be written to open file w/formatting info
//                   ... - formatting variable argument list
//
// Output Variable: function status return (TRUE- success, FALSE- error)
BOOL KEMETReportClass::WriteLineToReportFile(LPCTSTR lpszformatstr, ...)
{
      // assure a good valid string
      ASSERT(AfxIsValidString(lpszformatstr,FALSE));

      // check that a file is actually open
      if (!FileOpened || reportfilehandle == NULL)
            {
            AfxMessageBox("KEMETReportClass Warning!\nNo File Has Been Opened.\nCannot Write Line.",MB_OK | MB_ICONEXCLAMATION);
            return(FALSE);
            }

      // stuff the text string into a formatted CString
      CString ReportLineTextString;
      va_list arglist;
      va_start(arglist,lpszformatstr);
      ReportLineTextString.Format("%s",lpszformatstr,arglist);
      va_end(arglist);

      // now check for empty string
      // if not empty, spit it to the file, othewise, display a NULL string error message
      if (!ReportLineTextString.IsEmpty())
            fprintf(reportfilehandle,"%s",ReportLineTextString);
      else
            {
            AfxMessageBox("KEMETReportClass Warning!\nCannot Write A NULL Text Line.",MB_OK | MB_ICONEXCLAMATION);
            return(FALSE);
            }
      
AfxMessageBox(ReportLineTextString);
      return(TRUE);
}
0
Comment
Question by:maknight
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 6

Accepted Solution

by:
jpk041897 earned 30 total points
ID: 1397711
valists separate strings from eachoter using nulls, for instance:

"String 1"\0"String 2"\0"String 3"\0\0

Deafault constructors for CString would only read the first string in the va list.

You would either have to derive a class from CString and add your own constructor or add a method that woud parse the va list and implement the functionality you desire.
0

Featured Post

What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article surveys and compares options for encoding and decoding base64 data.  It includes source code in C++ as well as examples of how to use standard Windows API functions for these tasks. We'll look at the algorithms — how encoding and decodi…
What my article will show is if you ever had to do processing to a listbox without being able to just select all the items in it. My software Visual Studio 2008 crystal report v11 My issue was I wanted to add crystal report to a form and show…
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
How to fix incompatible JVM issue while installing Eclipse While installing Eclipse in windows, got one error like above and unable to proceed with the installation. This video describes how to successfully install Eclipse. How to solve incompa…

618 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question