Help with mfc

[ovidiucucu]

You've probably got the "System" font, which size can be modified only from the system settings. Or can be another font that does not support the size you have provided.
Anyway it's not a good idea to get the current font from the device context and modify its attributes "on the fly".
Just create your own font! Here is an example:

void CDemoSdiView::RenderText(CDC* pDC, int left, int top, const CString& strText)
{
    CFont font;
    font.CreatePointFont(80, _T("Verdana"));
    CFont* pOldFont = pDC->SelectObject(&font);
    int nOldMapMode = pDC->SetMapMode(MM_TEXT);

    CRect rc;
    // calculate the necessary rectangle
    pDC->DrawText(strText, rc, DT_LEFT|DT_TOP|DT_CALCRECT);
    // offset the rectangle to top-left coordinates
    rc.OffsetRect(left, top);
    // filally draw the text
    pDC->DrawText(strText, rc, DT_LEFT|DT_TOP);

    // restore DC status
    pDC->SetMapMode(nOldMapMode);
    pDC->SelectObject(pOldFont);
}

Additional notes:

• After drawing, do not forget to restore the initial DC status, as shown in the above example. Alternatively, you can use CDC::SaveDC and CDC::RestoreDC for doing that easier.
  

      // save the DC status    
      int nDCStatus = pDC->SaveDC();
      // ...
      // ...
      // restore DC status
      pDC->RestoreDC(nDCStatus);

• For simplicity, I used in my example CFont::CreatePointFont. If you want to also set other custom attributes, like weight for example, call CFont::CreateFont, CFont::CreateFontIndirect, or CFont::CreatePointFontIndirect. See CFont Class in Microsoft Learn documentation.
• The fizical size of a text depends on DC type and mapping mode. That's the reason I called CDC::SetMapMode. For more info, have a look at LOGFONT Structure documentation.