MessageBox doesnt appear

Hi. Does anyone know why is it that i always have to key "alt" before my MessageBox actually appears? My messagebox is created whenever my button is clicked. I tried making the button control topmost but it didnt work. Here is the code:

Code:

---

// function to create window
HWND mainFrame::createWindow(HINSTANCE hinst, int nCmdShow, UINT resPoolID, UINT title)
{
        HWND hwnd; // handler for window to be created
        TCHAR ClassName[MAX_RESOURCESTRING+1]; // window class name
        TCHAR wndTitle[MAX_RESOURCESTRING+1]; // window title
        HDC hDC;
        HBITMAP hBit;
        TEXTMETRIC tm;

        // load class name into ClassName
        LoadString(hinst,resPoolID,ClassName,DIM(ClassName));
        // load title name into title
        LoadString(hinst,title,wndTitle,DIM(wndTitle));

        hwnd = CreateWindowEx(0,                        // extended window style
                                                  ClassName,        // class name
                                                  wndTitle,                // title
                                                  WS_CLIPCHILDREN | WS_OVERLAPPEDWINDOW & ~WS_THICKFRAME & ~WS_MAXIMIZEBOX,        // window style
                                                  CW_USEDEFAULT,                // default x-pos of window                       
                                                  0,        // y-pos of window, set 0 and use showWindow() to determine later
                                                  MAX_SCREENWIDTH,        // width of window       
                                                  MAX_SCREENHEIGHT+ GetSystemMetrics(SM_CYMENU)+GetSystemMetrics(SM_CYCAPTION),        // height of window
                                                  NULL, // parent of window
                                                  LoadMenu(hinst, MAKEINTRESOURCE(resPoolID)),        // handle of menu
                                                  hinst,        //handle of application
                                                  this);        // user defined parameters, hardly any use for it
        if(!hwnd)
                return NULL;

        // make window appear
        ShowWindow(hwnd,nCmdShow);

        // Create a memory context for window
        //----------------------------------------------------//
        //1. get display context for window
        hDC = GetDC(hwnd);
        //2. create compatible memory for window
        memDC = CreateCompatibleDC(hDC);
        //3. load main bitmap for window
        hBit = LoadBitmap(GetWindowInstance(hwnd),MAKEINTRESOURCE(IDB_MAINSCREEN));
        //4. select main bitmap into memory DC
        //NOTE: MUST NOT DELETE BITMAP WHEN IT IS CURRENTLY SELECTED INTO A DC
        hOldBit = (HBITMAP)SelectObject(memDC,hBit);
        // 5. delete display context
        DeleteDC(hDC);
        //----------------------------------------------------//
        // ALTERNATE METHOD IS TO USE SAVEDC!!!


        // rich edit control for name input
        InitCommonControls();
        if(!LoadLibrary("riched20.dll"))
        return 0;

        hDC = GetDC(hEditCtl);
        GetTextMetrics(hDC,&tm);
        DeleteDC(hDC);

        hEditCtl = CreateWindowEx(0,
                                                                RICHEDIT_CLASS,
                                                                NULL,
                                                                WS_CHILD |ES_LEFT| WS_VISIBLE | ES_AUTOHSCROLL | ES_SUNKEN,
                                                                177,
                                                                284,
                                                                22*tm.tmAveCharWidth,
                                                                25,
                                                                hwnd,
                                                                (HMENU)ID_EDIT,
                                                                hinst,
                                                                NULL);

        if(!hEditCtl)
                MessageBox(hwnd,"Not working","not working",MB_ICONEXCLAMATION );

        // limit the number of character that edit control takes
        SendMessage(hEditCtl,EM_EXLIMITTEXT,0,15);
        // make edit control beep when max number of character is exceeded
        SendMessage(hEditCtl,EM_SETEDITSTYLE,SES_BEEPONMAXTEXT,SES_BEEPONMAXTEXT);

                        // create default push button
        button = CreateWindowEx(0,
                                                        _T("button"),
                                                        _T("Start"),
                                                        WS_CHILD | WS_VISIBLE | BS_DEFPUSHBUTTON,
                                                        350+15*tm.tmAveCharWidth,
                                                        284,
                                                        50,
                                                        25,
                                                        hwnd,
                                                        (HMENU)ID_BUTTON,
                                                        hinst,
                                                        NULL);

        // force main window to update
        UpdateWindow(hwnd);

        return hwnd;

}

void mainFrame::mainWindow_onCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify)
{
       
        switch(id)
        {case ID_FILE_EXIT:        DestroyWindow(hwnd);
                                        return;
        case ID_BUTTON: SetWindowPos(hwndCtl,HWND_TOP,0,0,0,0,SWP_NOMOVE|SWP_NOSIZE);
                            MessageBox(hwndCtl,"Not working","not working",MB_ICONEXCLAMATION | MB_TOPMOST );
                                  return;
        default: FORWARD_WM_COMMAND(hwnd,id,hwndCtl,codeNotify,DefWindowProc);
        }

}

---

case ID_BUTTON looks a bit suspect if it's intended to trap button click events; it may be that your MessageBox code is only fired with the 'alt' key due to a coincidence in id values.

Generally, to handle child control notifications check, with respect to your mainWindow_onCommand fn:

1. That hwndCtl is a non-NULL value - if it is NULL then the notification (codeNotify) is NOT from a control.
2. The value of codeNotify matches the notification you wish to handle. In the case of a button click event, that notification should be BN_CLICKED.
3. The value of id is the same as the id for the child control with handle hwndCtl.

This ensures that a particular notification for a specific control is properly handled.

See also WM_COMMAND.

[edit]removed extra 'handled'; I must like that word or something. :rolleyes: [/edit]

>>case ID_BUTTON looks a bit suspect if it's intended to trap button click events; it may be that your MessageBox code is only fired with the 'alt' key due to a coincidence in id values.

Actually the messagebox is created correctly, just that i needed to press "alt" to bring it on top of the main window. I am pretty sure i capture the button click events correctly, cos i replaced the code like this and gets the same problem:

Code:

---

        case ID_BUTTON: if(hwndCtl&& (codeNotify == BN_CLICKED))
                                        MessageBox(hwndCtl,"Not working","not working",MB_ICONEXCLAMATION | MB_TOPMOST );
                                        else
                                        FORWARD_WM_COMMAND(hwnd,id,hwndCtl,codeNotify,DefWindowProc);
                                        return;

---

I still have to pressed "alt" to make the messagebox to bring to foreground and not behind the main window.

However, i noticed if i remove the MoveWindow() statement when handling the WM_PAINT msg. My messagebox will appear correctly. But my edit control will always be painted over by the bitmap in memory DC. I needed the MoveWindow() statement to make sure my edit control appear again after the main window paints its client area.

Code:

---

void mainFrame::mainWindow_onPaint(HWND hwnd)
{
        PAINTSTRUCT ps;
        TEXTMETRIC tm;
        HDC hDC;

    hDC = GetDC(hEditCtl);
        GetTextMetrics(hDC,&tm);
        DeleteDC(hDC);

        // copy the bitmap in memory into display context
        hDC = BeginPaint(hwnd,&ps);
        BitBlt(hDC,0,0,MAX_SCREENWIDTH,MAX_SCREENHEIGHT,memDC,0,0,SRCCOPY|CAPTUREBLT);
        MoveWindow(hEditCtl,177,284,22*tm.tmAveCharWidth,25,TRUE);
        UpdateWindow(hEditCtl);
        UpdateWindow(button);
        EndPaint(hwnd,&ps);
       
}

---

Ok i managed to solve the problem but it left me with many doubts. Instead of using MoveWindow(), i used SetForegroundWindow():

Code:

---

void mainFrame::mainWindow_onPaint(HWND hwnd)
{
        PAINTSTRUCT ps;
        TEXTMETRIC tm;
        HDC hDC;

    hDC = GetDC(hEditCtl);
        GetTextMetrics(hDC,&tm);
        DeleteDC(hDC);

        // copy the bitmap in memory into display context
        hDC = BeginPaint(hwnd,&ps);
        BitBlt(hDC,0,0,MAX_SCREENWIDTH,MAX_SCREENHEIGHT,memDC,0,0,SRCCOPY|CAPTUREBLT);
// replaced with SetForegroundWindow()
        //MoveWindow(hEditCtl,177,284,22*tm.tmAveCharWidth,25,TRUE);
        SetForegroundWindow(hEditCtl);
        UpdateWindow(hEditCtl);
        UpdateWindow(button);
        EndPaint(hwnd,&ps);
       
}

---

I have a few questions:
- what changes did MoveWindow() make that my messagebox cannot show up above the main window.
-how come using

Code:

---

SetWindowPos(hEditCtl,HWND_TOP,0,0,0,0,SWP_NOMOVE|SWP_NOSIZE);

---

cannot make my edit control appear like MoveWindow() and SetForegroundWindow() can?
-why does the Bitblt() still paints over my edit control(and yet not the button control) despite i added WS_CLIPCHILDREN to my main window style? I even added CAPTUREBLT to the flag in BitBlt().

FYI, a 24bit bitmap that holds the background of my screen is selected in the memDC for BitBlt()

[EDIT] Argh i posted too soon. When i used SetForegroundWindow() instead, my edit control doesnt update itself when i tried to "backspace" some of the input i typed, unless i minimized it and restore it.

A word of caution: when you use GetDC to retrieve a device context handle, use ReleaseDC and not DeleteDC when you're finished with it.

yes i corrected that...Thanks.

Here is my amended code. I just found out if i hide the edit control before calling the messagebox, the messagebox can appear correctly. But i dont want to hide my edit control. Hope it provide more clues to my problem.

Code:

---

// function to create window
HWND mainFrame::createWindow(HINSTANCE hinst, int nCmdShow, UINT resPoolID, UINT title)
{
        HWND hwnd; // handler for window to be created
        TCHAR ClassName[MAX_RESOURCESTRING+1]; // window class name
        TCHAR wndTitle[MAX_RESOURCESTRING+1]; // window title
        HDC hDC;
        HBITMAP hBit;
        TEXTMETRIC tm;

        // load class name into ClassName
        LoadString(hinst,resPoolID,ClassName,DIM(ClassName));
        // load title name into title
        LoadString(hinst,title,wndTitle,DIM(wndTitle));

        hwnd = CreateWindowEx(0,                        // extended window style
                                                  ClassName,        // class name
                                                  wndTitle,                // title
                                                  WS_CLIPCHILDREN | WS_OVERLAPPEDWINDOW & ~WS_THICKFRAME & ~WS_MAXIMIZEBOX,        // window style
                                                  CW_USEDEFAULT,                // default x-pos of window                       
                                                  0,        // y-pos of window, set 0 and use showWindow() to determine later
                                                  MAX_SCREENWIDTH,        // width of window       
                                                  MAX_SCREENHEIGHT+ GetSystemMetrics(SM_CYMENU)+GetSystemMetrics(SM_CYCAPTION),        // height of window
                                                  NULL, // parent of window
                                                  LoadMenu(hinst, MAKEINTRESOURCE(resPoolID)),        // handle of menu
                                                  hinst,        //handle of application
                                                  this);        // user defined parameters, hardly any use for it
        if(!hwnd)
                return NULL;

        // make window appear
        ShowWindow(hwnd,nCmdShow);

        // Create a memory context for window
        //----------------------------------------------------//
        //1. get display context for window
        hDC = GetDC(hwnd);
        GetTextMetrics(hDC,&tm);// get textmetrics for creating window
        //2. create compatible memory for window
        memDC = CreateCompatibleDC(hDC);
        //3. load main bitmap for window
        hBit = (HBITMAP) LoadImage(GetWindowInstance(hwnd),
                                        MAKEINTRESOURCE(IDB_MAINSCREEN),
                                        IMAGE_BITMAP,
                                        MAX_SCREENWIDTH,
                                        MAX_SCREENHEIGHT,
                                        LR_CREATEDIBSECTION|LR_VGACOLOR);
        //4. select main bitmap into memory DC
        //NOTE: MUST NOT DELETE BITMAP WHEN IT IS CURRENTLY SELECTED INTO A DC
        hOldBit = (HBITMAP)SelectObject(memDC,hBit);
        // 5. delete display context
        ReleaseDC(hwnd,hDC);
        //----------------------------------------------------//
        // ALTERNATE METHOD IS TO USE SAVEDC!!!


        // rich edit control for name input
        InitCommonControls();
        if(!LoadLibrary("riched20.dll"))
        return 0;

        hEditCtl = CreateWindowEx(0,
                                                                RICHEDIT_CLASS,
                                                                NULL,
                                                                WS_CHILD |ES_LEFT| WS_VISIBLE | WS_CLIPSIBLINGS | ES_AUTOHSCROLL | ES_SUNKEN,
                                                                177,
                                                                284,
                                                                22*tm.tmAveCharWidth,
                                                                25,
                                                                hwnd,
                                                                (HMENU)ID_EDIT,
                                                                hinst,
                                                                NULL);

        if(!hEditCtl)
                MessageBox(hwnd,"Not working","not working",MB_ICONEXCLAMATION );

        // limit the number of character that edit control takes
        SendMessage(hEditCtl,EM_EXLIMITTEXT,0,15);
        // make edit control beep when max number of character is exceeded
        SendMessage(hEditCtl,EM_SETEDITSTYLE,SES_BEEPONMAXTEXT,SES_BEEPONMAXTEXT);

                        // create default push button
        hButton = CreateWindowEx(0,
                                                        _T("button"),
                                                        _T("Start"),
                                                        WS_CHILD | WS_VISIBLE |WS_CLIPSIBLINGS |BS_DEFPUSHBUTTON,
                                                        177 +23*tm.tmAveCharWidth,
                                                        284,
                                                        50,
                                                        25,
                                                        hwnd,
                                                        (HMENU)ID_BUTTON,
                                                        hinst,
                                                        NULL);

        // force main window to update
        UpdateWindow(hwnd);
        // set game window's parent window
    gf.setParent(hwnd);
       
        return hwnd;

}

---

Code:

---

int mainFrame::mainWindow_onPaint(HWND hwnd)
{
        PAINTSTRUCT ps;
        TEXTMETRIC tm;
        HDC hDC;

    hDC = GetDC(hEditCtl);
        GetTextMetrics(hDC,&tm);
        ReleaseDC(hwnd,hDC);

        // copy the bitmap in memory into display context
        hDC = BeginPaint(hwnd,&ps);
        BitBlt(hDC,0,0,MAX_SCREENWIDTH,MAX_SCREENHEIGHT,memDC,0,0,SRCCOPY| CAPTUREBLT);       
        EndPaint(hwnd,&ps);
       
        MoveWindow(hEditCtl,177,284,22*tm.tmAveCharWidth,25,TRUE);
        UpdateWindow(hEditCtl);
        UpdateWindow(hButton);
       
        if(hGame)
        UpdateWindow(hGame);

        return 0;
       
}

---

Code:

---

void mainFrame::mainWindow_onCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify)
{
       
        switch(id)
        {case ID_FILE_EXIT:        DestroyWindow(hwnd);
                                                return;
        case ID_BUTTON: if( (hwndCtl == hButton) && (codeNotify == BN_CLICKED) )               
                                        {

                                        ShowWindow(hEditCtl,SW_HIDE);
                                        // create the game window, IGNORE THIS FIRST
                                        //gf.createWindow(getHinst(),0,IDR_GAME,0);
                                        MessageBox(hwndCtl,"Not working","not working",MB_ICONEXCLAMATION | MB_TOPMOST | MB_SETFOREGROUND);
                                        }
                                        else
                                        FORWARD_WM_COMMAND(hwnd,id,hwndCtl,codeNotify,DefWindowProc);
                                        break;
        default: FORWARD_WM_COMMAND(hwnd,id,hwndCtl,codeNotify,DefWindowProc);
        }

}

---

Hi i am taking this chance to bump the thread. Been trying to solve my "edit control not updating and messagebox not appearing" problem for a few days. Really need some help here.

On top of that, i need to know why doesnt my compiler recognize all constants for normal character keys like VK_A,VK_B, etc as an identifier. Isnt it defined somewhere like in winuser.h?

Thanks.

Code:

---

C:\Documents and Settings\Edmund\My Documents\game and animation\edtris\gameFrame.cpp(436) : error C2065: 'VK_Q' : undeclared identifier
C:\Documents and Settings\Edmund\My Documents\game and animation\edtris\gameFrame.cpp(436) : error C2051: case expression not constant
C:\Documents and Settings\Edmund\My Documents\game and animation\edtris\gameFrame.cpp(437) : error C2065: 'VK_W' : undeclared identifier
C:\Documents and Settings\Edmund\My Documents\game and animation\edtris\gameFrame.cpp(437) : error C2051: case expression not constant

---

Code:

---

MessageBox(hwndCtl,"Not working","not working",MB_ICONEXCLAMATION | MB_TOPMOST | MB_SETFOREGROUND);

---

Try using hwnd instead of hwndCtl as the parent window argument to MessageBox.

--

>> On top of that, i need to know why doesnt my compiler recognize all constants for normal character keys like VK_A,VK_B, etc as an identifier. Isnt it defined somewhere like in winuser.h? <<

Just use 'A', 'B', '1', '2', etc. Letters must be uppercase.

The problem is with my messagebox and edit control. If i dont call the SetWindowPos() on the edit control in the mainWindow_onPaint function, the messageBox will be able to appear but the edit control cannot update itself.

However, if i have the SetWindowPos() called, the caret in the edit control doesnt blink(it appear just as a non blinking vertical bar) and it can update itself when i typed something. But the messageBox will not appear unless i press "alt". I tried to pass the main window handle, edit window handle, button window handle and NULLto the messageBox. None of it work.

Code:

---

int mainFrame::mainWindow_onPaint(HWND hwnd)
{
        PAINTSTRUCT ps;
        TEXTMETRIC tm;
        HDC hDC;

    hDC = GetDC(hEditCtl);
        GetTextMetrics(hDC,&tm);
        ReleaseDC(hwnd,hDC);

        // copy the bitmap in memory into display context
        hDC = BeginPaint(hwnd,&ps);
        EndPaint(hwnd,&ps);
       
        //SetWindowPos(hEditCtl,HWND_BOTTOM,177,284,22*tm.tmAveCharWidth,25,SWP_NOZORDER|SWP_NOSIZE|SWP_NOMOVE);       
   
        // update controls
        UpdateWindow(hEditCtl);
        UpdateWindow(hButton);
        if(IsWindow(hGame))
        UpdateWindow(hGame);

        return 0;
       
}

---