C / C++ / MFC

<br />
        <small>MY_TRACE (("CreateService() failed; %s\n", my_strerror(GetLastError())));</small><br />

cedricvictor wrote:

but my application still work,

int nX = tRect.left + tRect.Width() / 2;
int nY = tRect.top +  tRect.Height() / 2;
pDC->BitBlt(nX, nY, tRect.Width()/3, tRect.Height()/3, &MemDC, 
         0, 0, SRCCOPY);

When a memory device context is created, GDI automatically selects a 1-by-1 monochrome stock bitmap for it. GDI output functions can be used with a memory device context only if a bitmap has been created and selected into that context.

void CDrawTextTstDlg::OnTimer(UINT_PTR nIDEvent)
{
CDC *pDC; 
CRect tRect;
CDC   MemDC; 

pDC = this->GetDC();	
GetClientRect(&tRect);
MemDC.CreateCompatibleDC(NULL); 
	
CBitmap bmp;
bmp.CreateCompatibleBitmap(&MemDC, tRect.Width(), tRect.Height());
CBitmap *oldBitmap = MemDC.SelectObject(&bmp);
MemDC.SetBkMode(TRANSPARENT);
	
if (gtest == 0 ){
        MemDC.SetTextColor(RGB(255,255,255));
	MemDC.DrawText(_T("My Test"),&tRect,DT_CENTER|DT_VCENTER|DT_SINGLELINE);
	MemDC.SetTextColor(RGB(255,0,0));
		       MemDC.DrawText(_T("TEST"),&tRect,DT_CENTER|DT_VCENTER|DT_SINGLELINE);
}
else  {
	MemDC.SetTextColor(RGB(255,255,255));
		MemDC.DrawText(_T("TEST"),&tRect,DT_CENTER|DT_VCENTER|DT_SINGLELINE);
MemDC.SetTextColor(RGB(0,150,0));
MemDC.DrawText(_T("My Test"),&tRect,DT_CENTER|DT_VCENTER|DT_SINGLELINE);

}
	
pDC->BitBlt(0, 0, tRect.Width(), tRect.Height(), &MemDC, 
         0, 0, SRCCOPY);
m_Seconds++;
m_TimerEcho.Format(_T("%d: Seconds have passed"), m_Seconds); 
gtest ^= 1;
	
MemDC.SelectObject(oldBitmap);
bmp.DeleteObject();
MemDC.DeleteDC();
ReleaseDC(pDC);

CDialog::OnTimer(nIDEvent);
}

bmp.CreateCompatibleBitmap(&MemDC, tRect.Width(), tRect.Height());

CRect outRect;
m_myDrawingRectControl.GetWindowRect(outRect);
ScreenToClient(outRect);

void CDynamicShowTextDlg::OnTimer(UINT nIDEvent)
{ 
   CRect outRect;
   m_myDrawingRectControl.GetWindowRect(outRect);
   ScreenToClient(outRect);

   InvalidateRect(outRect);
}


void CDynamicShowTextDlg::OnPaint() 
{
     if (IsIconic())
     {
     ...}
   else
   {
      CRect outRect;
      m_myDrawingRectControl.GetWindowRect(outRect);
      ScreenToClient(outRect);

      CPaintDC dc(this); // device context for painting

      ...
do your drawing here.
use dc as the source for your CreateCompatible* stuff
     ...
      CDialog::OnPaint();
     }

IDD_ECHOBUTTONEVENT_DIALOG DIALOGEX 0, 0, 320, 200
...
BEGIN
...
     LTEXT           "Static",IDC_STATIC_TXT1,89,59,98,26
...
END

CRect outRect;
CStatic* pTxt1Static;
pTxt1Static = (CStatic*)GetDlgItem(IDC_STATIC_TXT1);
pTxt1Static->GetWindowRect(&outRect);
ScreenToClient(&outRect);
InvalidateRect(&outRect);
UpdateData(FALSE);

if (IsIconic()) {
...
}
else
{
	CRect outRect;
	CStatic* pTxt1Static;
	pTxt1Static = (CStatic*)GetDlgItem(IDC_STATIC_TXT1);
	pTxt1Static->GetWindowRect(&outRect);
	ScreenToClient(&outRect);

	CPaintDC dc(pTxt1Static); 
	//dc.SetTextColor(RGB(255,255,255));
	dc.SetTextColor(RGB(255,0,0));
	dc.SetBkMode(TRANSPARENT);
		
	dc.DrawText(_T("My Test"),&outRect,DT_CENTER|DT_VCENTER);
		
	CDialogEx::OnPaint();
}

econy wrote:

But, the string "My Test" 's position is not at same position of Static text(IDC_STATIC_TXT1).

offset I guess is about 50 to 100 pixel.

econy wrote:

 

And if I change CPaintDC dc(pTxt1Static) to CPaintDC dc(this),