C / C++ / MFC

Start -->
  All Programs --> 
    Microsoft Platform SDK <release date> --> 
      Platform SDK Documentation

double old = atof(&string); // Get current value
old += new; // Add new value to old value
string.Format(_T("%f"),old); // replace sting with new value

CString do2CStr(double var,int ndec)<br />
{<br />
	int  decimal, sign;<br />
	char *buffer;<br />
	buffer = _fcvt( var, ndec ,&decimal, &sign );<br />
	int len=strlen(buffer);<br />
	CString number(buffer);	<br />
	CString valor;<br />
	if(sign)//negative number<br />
		valor="-"+number.Left(decimal)+"."+number.Right(len-decimal);<br />
	else<br />
		valor=number.Left(decimal)+"."+number.Right(len-decimal);<br />
	return valor;<br />
<br />
}

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

bool CdotnetDlg::ValidEmail(CString strMail)
{
    #pragma push_macro("new")
    #undef new
    
    CString strPattern = "[\\w]+@[\\w]+.[\\w]{2,3}";
    Match* pMatch =Regex::Match(strMail,strPattern);

    #pragma pop_macro("new")
    return pMatch->Success;
}

//
//  Purpose:
//    Copies a bitmap transparently onto the destination DC.
//
//  Returns:
//    None
//
void FooButton::TransparentBlt
  (HDC      hdcDest,            // destination device context
   int      nXDest,             // x-coord of destination rectangle's upper-left corner
   int      nYDest,             // y-coord of destination rectangle's upper-left corner
   int      nWidth,             // width of destination rectangle
   int      nHeight,            // height of destination rectangle
   HBITMAP  hBitmap,            // source bitmap
   int      nXSrc,              // x-coord of source rectangle's upper-left corner
   int      nYSrc,              // y-coord of source rectangle's upper-left corner
   COLORREF colorTransparent,   // transparent color
   HPALETTE hPal)               // logical palette to be used with bitmap (may be NULL)
{
  CDC dc, memDC, maskDC, tempDC;
  dc.Attach( hdcDest );
  maskDC.CreateCompatibleDC(&dc);
  CBitmap maskBitmap;
 
  // These store return of SelectObject() calls
  CBitmap* pOldMemBmp = NULL;
  CBitmap* pOldMaskBmp = NULL;
  HBITMAP hOldTempBmp = NULL;
 
  memDC.CreateCompatibleDC (&dc);
  tempDC.CreateCompatibleDC (&dc);
  CBitmap bmpImage;
  bmpImage.CreateCompatibleBitmap (&dc, nWidth, nHeight);
  pOldMemBmp = memDC.SelectObject (&bmpImage);
 
  // Select and realize the palette
  if (dc.GetDeviceCaps (RASTERCAPS) & RC_PALETTE && hPal) {
     ::SelectPalette( dc, hPal, FALSE );
     dc.RealizePalette();
     ::SelectPalette( memDC, hPal, FALSE );
  }
 
  hOldTempBmp = (HBITMAP) ::SelectObject (tempDC.m_hDC, hBitmap);
  memDC.BitBlt (0, 0, nWidth, nHeight, &tempDC, nXSrc, nYSrc, SRCCOPY);
 
  // Create monochrome bitmap for the mask
  maskBitmap.CreateBitmap (nWidth, nHeight, 1, 1, NULL);
  pOldMaskBmp = maskDC.SelectObject (&maskBitmap);
  memDC.SetBkColor (colorTransparent);
 
  // Create the mask from the memory DC
  maskDC.BitBlt (0, 0, nWidth, nHeight, &memDC, 0, 0, SRCCOPY);
 
  // Set the background in memDC to black. Using SRCPAINT with black
  // and any other color results in the other color, thus making
  // black the transparent color
  memDC.SetBkColor (RGB (0,0,0));
  memDC.SetTextColor (RGB (255,255,255));
  memDC.BitBlt (0, 0, nWidth, nHeight, &maskDC, 0, 0, SRCAND);
 
  // Set the foreground to black. See comment above.
  dc.SetBkColor (RGB (255,255,255));
  dc.SetTextColor (RGB (0,0,0));
  dc.BitBlt (nXDest, nYDest, nWidth, nHeight, &maskDC, 0, 0, SRCAND);
 
  // Combine the foreground with the background
  dc.BitBlt (nXDest, nYDest, nWidth, nHeight, &memDC, 0, 0, SRCPAINT);
 
  if (hOldTempBmp)
     ::SelectObject (tempDC.m_hDC, hOldTempBmp);
  if (pOldMaskBmp)
     maskDC.SelectObject (pOldMaskBmp);
  if (pOldMemBmp)
     memDC.SelectObject (pOldMemBmp);
 
  dc.Detach();
}

// Win 3.x and above
// Note: This technique may not necessarily work on printer devices.

// Create temporary Bitmaps
CBitmap bmpMask;
if( !bmpMask.CreateBitmap(
    bmSrc.bmWidth, bmSrc.bmHeight, 1, 1, NULL) )
{
    return FALSE;
}

CBitmap bmpTemp;
if( !bmpTemp.CreateCompatibleBitmap(
    pdcDest, bmSrc.bmWidth, bmSrc.bmHeight) )
{
    return FALSE;
}

// Create temporary DCs and select bitmaps into them
CWorkDC dcTemp(pdcDest, &bmpTemp);
CWorkDC dcMask(pdcDest, &bmpMask);

// Use temporary DC to reduce flicker
if( dcTemp.BitBlt(0, 0, bmSrc.bmWidth, bmSrc.bmHeight,
    pdcDest, xDest, yDest, SRCCOPY) )
{
    // If we made it here there should be no more possible problems

    // Create mask using crTransparent
    dcSrc.SetBkColor(crTrans);
    dcMask.BitBlt(0, 0, bmSrc.bmWidth, bmSrc.bmHeight,
        &dcSrc, 0,0, SRCCOPY);

    // Draw bitmap using mask
    dcTemp.BitBlt(0, 0, bmSrc.bmWidth, bmSrc.bmHeight,
        &dcSrc, 0, 0, SRCINVERT);
    dcTemp.BitBlt(0, 0, bmSrc.bmWidth, bmSrc.bmHeight,
        &dcMask, 0, 0, SRCAND);
    dcTemp.BitBlt(0, 0, bmSrc.bmWidth, bmSrc.bmHeight,
        &dcSrc, 0, 0, SRCINVERT);

    // Copy Temporary DC to Destination DC
    pdcDest->BitBlt(xDest, yDest, nWidth, hHeight,
        &dcTemp, 0, 0, SRCCOPY);
}