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Formatted MessageBox/AfxMessageBox

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20 Oct 2010CPOL 44.2K   9   1
Need to Format/sprintf a string before displaying a messagebox? Here is solution!
You often need to format a string and populate it with relevant data before displaying a message box. For example
int nAge = 27;
TCHAR sName[]="Ajay";
float nSalary = 12500.50;

// Declare variable
CString strMessage;<br>
// Format
strMessage.Format( _T("Name is %s, Age is %d, and salary is %.2f"), 
    sName, nAge, nSalary);<br>
// Then display.
AfxMessageBox(strMessage);</br></br>
What if this can be acheived by single statement:
AfxMessageBoxFormatted(_T("Name is %s, Age is %d, and salary is %.2f"), 
   sName, nAge, nSalary);
And here is implementation of AfxMessageBoxFormatted:
void AfxMessageBoxFormatted(LPCTSTR pFormatString, ...)
{
    va_list vl;
    va_start(vl, pFormatString);<br>
    CString strFormat;
    strFormat.FormatV(pFormatString, vl); // This Line is important!<br>
    // Display message box.	
    AfxMessageBox(strFormat);
}</br></br>
If you don't you MFC, or don't want to use, you can implement MessageBoxFormatted as:
void MessageBoxFormatted(HWND hWnd, LPCTSTR pCaption, LPCTSTR pFormatString, ...)
{
    va_list vl;
    va_start(vl, pFormatString);<br>    
    TCHAR strFormat[1024]; // Must ensure size!<br>

    // Generic version of vsprintf, works for both MBCS and Unicode builds 
    _vstprintf(strFormat, pFormatString, vl);<br>	
    // Or use following for more secure code
    // _vstprintf_s(strFormat, sizeof(strFormat), pFormatString, vl)<br>
    ::MessageBox(hWnd, strFormat, pCaption,MB_ICONINFORMATION);
}</br></br></br></br>
And use it as:
MessageBoxFormatted(NULL,  // Or a valid HWND
    _T("Information"),
    _T("Name is %s, Age is %d, and salary is %.2f"),
    sName, nAge, nSalary);
If you don't understand stuff like TCHAR, LPCTSTR, _T, you better read this Tip/Trick: What are TCHAR, WCHAR, LPSTR, LPWSTR, LPCTSTR etc?[^]

License

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


Written By
Software Developer (Senior)
India India
Started programming with GwBasic back in 1996 (Those lovely days!). Found the hidden talent!

Touched COBOL and Quick Basic for a while.

Finally learned C and C++ entirely on my own, and fell in love with C++, still in love! Began with Turbo C 2.0/3.0, then to VC6 for 4 years! Finally on VC2008/2010.

I enjoy programming, mostly the system programming, but the UI is always on top of MFC! Quite experienced on other environments and platforms, but I prefer Visual C++. Zeal to learn, and to share!

Comments and Discussions

 
Questionvery good trick! Pin
Southmountain23-Feb-20 9:30
Southmountain23-Feb-20 9:30 

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