dev-cpp-users

[Vlada D. <dj...@im...>]

Hi, everybody
Here's my problem: I'm trying to write a simple drawing app (just for =
exercise) and so far its been going OK. I can draw lines in client area =
in different colors, but when ever I minimize or maximize the window, or =
something similar happenes, all the content of the window is gone. I =
tried to use a memory DC an bitmap to save the contents in, and BitBlt =
it back in response to WM_PAINT message, but the program just "froze". =
Can anybody give me a hint how to do it? Here's the code used for =
drawing lines without any restoring parts:

        case WM_MOUSEMOVE:
        {
            switch(iTool)           /* iTool is used for dtetrmining =
which drawing tool is selected(line, rect etc.)*/
            {
                case 0:
                {
                   if(wParam=3D=3DMK_LBUTTON)    /*if line is selected =
(itool=3D0) and left button presed*/
                   {
                         HDC hDC=3DGetDC(hwnd);           =20
                      =20
                       HPEN =
hPen=3DCreatePen(PS_SOLID,iCurWidth,crCurColor);
                       HPEN hOldPen=3D(HPEN)SelectObject(hDC,hPen);
                       CLine* pLine=3Dnew =
CLine(ptPrevPos,MAKEPOINTS(lParam),iCurWidth,crCurColor); /*create new =
line object*/
                       pLine->DrawLine(hDC);
                       ptPrevPos=3DMAKEPOINTS(lParam);
                       SelectObject(hDC,hOldPen);
                       DeleteDC(hDC);
                   }
                }
                break;
                case 1: /* nothing here yet*/
                break;
            }
        }