Button with BW_OWNERDRAW make nonsens if i use a Timer Function

[rommi]

Hi everybody,
i have a program that has two buttons. The first button shows a part of the calculator (calc.exe small view) window and the other button has a bitmap on it and when i click on the button the bitmap is changing.
Ive created both buttons with the BS_OWNERDRAW style and i use the DRWAWITEM function for their properties. Actually everything is ok when i start the program and all works fine. But after one or two minutes the bitmap on the bitmap-button is away and if i want to resize or move the mainwindow the hole desktop-background is redrawing.

I guess the timer-function is the reason for this problem cause if i disable the timer-function the problem dont exist anymore. But i need a timer-function in my program cause the button who shows a part of the calculator (calc.exe small view) should always refreshed (at least every second) automaticly (without any click). I tried to find a solution for this error over google but until now i didnt get any hint to solve that problem. Maybe anybody knows what is wrong in my scrpit and let me know what is the cause for the problem and how can i change it. Thanks a lot for every help in advance! best regards, rommi

#include <windows.h>
#include <stdio.h>
#include <tchar.h>
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LPCSTR lpszAppName          = "AppName";
char szNewButtonClassName[] = "newbutton";
HINSTANCE hInstance;
 
HWND hWnd;
HWND *btn                   = new HWND[100];
HWND hwndcalc;
HDC hdccalc;
HDC CopyDC;
 
const UINT Timer1           = 1;
TCHAR title[2];
HBITMAP bmpcalc;
 
// ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
// XXXXXX                                       Sub`s                                                           XXXXXXXX
// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
int DrawItem(UINT wParam,LPARAM lParam)
{
    LPDRAWITEMSTRUCT lpdis = (DRAWITEMSTRUCT*)lParam;
    HDC hdca = ((LPDRAWITEMSTRUCT)(lParam))->hDC;
    HDC hdcMem = CreateCompatibleDC(hdca);
    HBITMAP hBitmap;
 
    //XXX Buttons sunken und raise 
    DrawEdge(lpdis->hDC, &lpdis->rcItem,(lpdis->itemState & ODS_SELECTED ? EDGE_SUNKEN : EDGE_RAISED ), BF_RECT);
 
 
    if (((LPDRAWITEMSTRUCT)(lParam))->itemState & ODS_SELECTED){}
    else
    {
        switch(lpdis->CtlID)        //XXXX Abfrage Kontroll-ID
        {
            default:
 
                if( lpdis->CtlID == 0)  // Button mit Bild
                {
                    ZeroMemory(title, sizeof(title));
                    GetWindowText(btn[lpdis->CtlID], title, sizeof(title)/sizeof(title[0]));
                    if(_tcsstr(title, _T("F")))
                    {
                        hBitmap = (HBITMAP)LoadImage(0,"c:\\F.bmp",IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
                        SelectObject (hdcMem, hBitmap);
                        BitBlt (hdca, 0, 0, 30, 30, hdcMem, 0, 0, SRCCOPY) ;
                    }
                    else if (_tcsstr(title, _T("X")))
                    {
                        hBitmap = (HBITMAP)LoadImage(0,"c:\\X.bmp",IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
                        SelectObject (hdcMem, hBitmap);
                        BitBlt (hdca, 0, 0, 30, 30, hdcMem, 0, 0, SRCCOPY) ;
                    }
                break;
                }
                else if( lpdis->CtlID == 1 )    // Button mit dem Calc-Ausschnitt
                {
                    BitBlt (hdca,20,10,70,25,hdccalc,180, 40,SRCCOPY);  
                }
 
            break;
        }
    }
return 1;
}
 
 
void refresh()
{
    InvalidateRect(hWnd, NULL, TRUE);
}
 
// ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
// XXXXXX                                       Main                                                            XXXXXXXX
// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow)
{
    //XXXX für den Button mit dem Calculator-Ausschnitt
    hwndcalc = FindWindow( 0, "Rechner");
    hdccalc = GetWindowDC(hwndcalc);
    CopyDC = CreateCompatibleDC (hdccalc);
    bmpcalc = CreateCompatibleBitmap (hdccalc,70 ,25 );
    SelectObject (CopyDC, bmpcalc);
 
    //XXXX Button-Klasse (Doppel-Klick etc. modifiziert)
    WNDCLASS ClassNewButton;
    if( GetClassInfo(hInstance, "button",&ClassNewButton) )
    {
        ClassNewButton.hCursor = LoadCursor(NULL, IDC_HAND);
        ClassNewButton.lpszClassName = szNewButtonClassName;
        ClassNewButton.style &= ~((UINT)CS_DBLCLKS);// ****** turn off CS_DBLCLKS style
        RegisterClass(&ClassNewButton);
    }
 
    //XXXXX Main-Klasse
    MSG         msg;
    WNDCLASSEX  wc;
 
    wc.cbSize        =  sizeof(WNDCLASSEX);
    wc.style         =  CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc   =  WndProc;
    wc.cbClsExtra    =  0;
    wc.cbWndExtra    =  0;
    wc.hInstance     =  hInstance;
    wc.hCursor       =  LoadCursor(NULL,IDC_ARROW);
    wc.hIcon         =  LoadIcon(NULL, IDI_APPLICATION);
    wc.hbrBackground =  (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszClassName =  lpszAppName;
    wc.lpszMenuName  =  lpszAppName;
    wc.hIconSm       =  LoadIcon(NULL, IDI_APPLICATION);
    if( RegisterClassEx(&wc) == 0) return 0;
 
    //XXXX Erstell das Haupt-Fenster
    hWnd = CreateWindowEx(WS_EX_COMPOSITED,lpszAppName,"Main",WS_OVERLAPPEDWINDOW,200,200,208,126,NULL,NULL,hInstance,NULL);
    ShowWindow(hWnd, iCmdShow);
    UpdateWindow(hWnd);
 
    //XXXX Erstell die Buttons
    btn[0] = CreateWindow(szNewButtonClassName,"F",WS_CHILD|WS_VISIBLE|BS_OWNERDRAW,0,0,100,100,hWnd,(HMENU)0,hInstance,NULL);
    btn[1] = CreateWindow(szNewButtonClassName,"C",WS_CHILD|WS_VISIBLE|BS_OWNERDRAW,100,0,100,100,hWnd,(HMENU)1,hInstance,NULL);
 
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}
 
// ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
// XXXXXX                                       Callback Main                                                   XXXXXXXX
// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
LRESULT CALLBACK WndProc(HWND hWnd, UINT umsg, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT ps;
    switch (umsg)
    {
        //_________________________________________
        case WM_CREATE:
        {
                SetTimer(hWnd, Timer1, 20, NULL);
        }return 0;
        //_________________________________________
        case WM_TIMER:
        {
            refresh();
        }break;
        //_________________________________________    
        case WM_DESTROY:
        {
            KillTimer(hWnd, Timer1);
            PostQuitMessage(0);
        }return 0;
        //_________________________________________
        case WM_DRAWITEM:
        {
                DrawItem(wParam,lParam);
        }break;
        //_________________________________________
        case WM_COMMAND:
        {
            switch(LOWORD(wParam))
            {
                default:
                {
                    //XXX Statusabfrage des Buttons mit dem Bild
                    if( lParam == (LPARAM)btn[wParam])
                    {
                        ZeroMemory(title, sizeof(title));
                        GetWindowText(btn[wParam], title, sizeof(title)/sizeof(title[0]));
 
                        if(_tcsstr(title, _T("X"))){SetWindowText(btn[wParam],"F");}
                        else{SetWindowText(btn[wParam],"X");}
                    }
                }break;
            }
        }
        //_________________________________________
        case WM_PAINT:
        {
            BeginPaint(hWnd, &ps);
                // mach was
            EndPaint(hWnd, &ps);
 
        }break;
 
    }return DefWindowProc(hWnd, umsg, wParam, lParam);
}

[Igor Vartanov]

after one or two minutes the bitmap on the bitmap-button is away and if i want to resize or move the mainwindow the hole desktop-background is redrawing.

It's worth to doublecheck for GDI resource leak.

[VladimirF]

It's worth to doublecheck for GDI resource leak.

... or at least to single-check DrawItem() function - none of the GDI resources created there are deleted.

[rommi]

Thanks for your reply! I knew that ive forgotten something Ok now i have made the declaration of hdca, hdcMem and hBitmap global and delete all Objekts again on the end of the DrawItem() function. Now its running well ( i hope..)

Thanks a lot for your comments and hints!!
till next, regards, rommi

[Igor Vartanov]

BTW, there's no need to load images each time you draw. See my bmpbtn sample I gave you before in some other thread.

[rommi]

@Igor thanks for the additional hint! regards,rommi