Copy a bitmap from the source device context to this current device context.

I am using Microsoft Visual C++ 6.0.

I would like to draw a solid color square at the dialog, so I create a
function DrawSquare(), and use BitBlt() to copy a bitmap from the memory
device context to this current device context.

If I put the function DrawSquare() inside of OnInitDialog(), I could not see
the solid color square shown in the dialog. Otherwise if I put it into
OnTimer(), I can see the solid color square. However, I only want this
function being called once, instead of repeatedly by the timer, could
anybody please let me know how I can solve the problem? Should I put the
function DrawSquare() inside of any other function so it can only be called
once?

Thanks.

John



BOOL C***Dialog::OnInitDialog()
{
CDialog::OnInitDialog();

//The Solid Box will not be shown after called.
DrawSquare();

return TRUE;
}


void CPocketMax_PCDlg::OnTimer(UINT nIDEvent)
{
CDialog::OnTimer(nIDEvent);

//The Solid Box will be shown after called.
DrawSquare();
}



BOOL C***Dialog::DrawSquare()
{
CClientDC clientDC (this);

//Create Memory DC.
CDC dlgDC;
dlgDC.CreateCompatibleDC(&clientDC);

//Define the Memory Bitmap. Required!
CBitmap memBitmap;
memBitmap.CreateCompatibleBitmap (&clientDC, 240, 320); //Width, Height
dlgDC.SelectObject (&memBitmap);


CBrush * greyBr = new CBrush ( RGB (150,150,150));

int xStart = 0;
int yStart = 0;
int xEnd   = 240;
int yEnd   = 200;


//Draw Background
CRect rc(xStart, yStart, xEnd ,yEnd) ;
dlgDC.FillRect( &rc, greyBr); //Useful, to fill the background



clientDC.BitBlt(xStart, yStart, 240, 200, & dlgDC, xStart, yStart,
SRCCOPY) ;


// Be sure to release the DC!
ReleaseDC(&clientDC);
DeleteObject(clientDC);
ReleaseDC(&dlgDC);
DeleteObject(dlgDC);
memBitmap.DeleteObject();


greyBr->DeleteObject();

UpdateData (FALSE);



return TRUE;
}

}

I would think you'd want to call DrawSquare() in your WM_PAINT handler for
the dialog.

-Jayme

"JohnL" <hiliuzhe@hotmail.com> wrote in message
news:uCbguBRnEHA.1248@TK2MSFTNGP09.phx.gbl...
> I am using Microsoft Visual C++ 6.0.
>
> I would like to draw a solid color square at the dialog, so I create a
> function DrawSquare(), and use BitBlt() to copy a bitmap from the memory
> device context to this current device context.
>
> If I put the function DrawSquare() inside of OnInitDialog(), I could not
see
> the solid color square shown in the dialog. Otherwise if I put it into
> OnTimer(), I can see the solid color square. However, I only want this
> function being called once, instead of repeatedly by the timer, could
> anybody please let me know how I can solve the problem? Should I put the
> function DrawSquare() inside of any other function so it can only be
called
> once?
>
> Thanks.
>
> John
>
>
>
> BOOL C***Dialog::OnInitDialog()
> {
>  CDialog::OnInitDialog();
>
> //The Solid Box will not be shown after called.
> DrawSquare();
>
>  return TRUE;
> }
>
>
> void CPocketMax_PCDlg::OnTimer(UINT nIDEvent)
> {
>  CDialog::OnTimer(nIDEvent);
>
> //The Solid Box will be shown after called.
> DrawSquare();
> }
>
>
>
> BOOL C***Dialog::DrawSquare()
> {
> CClientDC clientDC (this);
>
>  //Create Memory DC.
>  CDC dlgDC;
>  dlgDC.CreateCompatibleDC(&clientDC);
>
>  //Define the Memory Bitmap. Required!
>  CBitmap memBitmap;
>  memBitmap.CreateCompatibleBitmap (&clientDC, 240, 320); //Width, Height
>  dlgDC.SelectObject (&memBitmap);
>
>
>  CBrush * greyBr = new CBrush ( RGB (150,150,150));
>
>     int xStart = 0;
>     int yStart = 0;
>     int xEnd   = 240;
>     int yEnd   = 200;
>
>
>  //Draw Background
>  CRect rc(xStart, yStart, xEnd ,yEnd) ;
>  dlgDC.FillRect( &rc, greyBr); //Useful, to fill the background
>
>
>
>     clientDC.BitBlt(xStart, yStart, 240, 200, & dlgDC, xStart, yStart,
> SRCCOPY) ;
>
>
>  // Be sure to release the DC!
>  ReleaseDC(&clientDC);
>     DeleteObject(clientDC);
>   ReleaseDC(&dlgDC);
>     DeleteObject(dlgDC);
>     memBitmap.DeleteObject();
>
>
>    greyBr->DeleteObject();
>
>     UpdateData (FALSE);
>
>
>
>     return TRUE;
> }
>
> }
>
>
>

Thanks, Jayme,

You are right, I forgot WM_PAINT and WM_SIZE.

John


"Jayme Pechan" <jayme.pechan@whitefeld.com> wrote in message
news:eMKknHRnEHA.2764@TK2MSFTNGP11.phx.gbl...
> I would think you'd want to call DrawSquare() in your WM_PAINT handler for
> the dialog.
>
> -Jayme
>
> "JohnL" <hiliuzhe@hotmail.com> wrote in message
> news:uCbguBRnEHA.1248@TK2MSFTNGP09.phx.gbl... 
> see 
> called 
>
>