WM_CAPTION causing CreateWindowEx() to fail.

Hey all!

I just started a new project, and I came across a problem. I think the title explains it all. All I want to do is create a window at the moment, with the standard code everyone uses from www.winprog.org. Anyways, I tried to change the WS to WS_OVERLAPPEDWINDOW, but an error message came up saying that the window could not be created. So I split OVERLAPPEDWINDOW up into WS_OVERLAPPED, WS_CAPTION, WS_SYSMENU, and WS_MINIMIZEBOX, to see which one was causing the problem. It works fine without WS_CAPTION, in that no error messages came up, but I was very annoyed when I couldn't see the window. Ideally, (sp?) I need to get this problem fixed, or another WS that has the same effect on the window as CAPTION.

Any one know what's wrong?

Cheers for any help provided.
Necrofear :cool:

Show us some code? Did you call ShowWindow() on the created window?

Code:

---


#include <windows.h>

const char g_szClassName[] = "myWindowClass";

// Step 4: the Window Procedure

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    { 
        case WM_CLOSE:
            DestroyWindow(hwnd);
            break;
       
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
       
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
   
    return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
    LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wc;
    HWND hwnd;
    MSG Msg;

    //Step 1: Registering the Window Class
   
    wc.cbSize        = sizeof(WNDCLASSEX);
    wc.style        = 0;
    wc.lpfnWndProc  = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance    = hInstance;
    wc.hIcon        = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor      = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = g_szClassName;
    wc.hIconSm      = LoadIcon(NULL, IDI_APPLICATION);

    if(!RegisterClassEx(&wc))
    {
        MessageBox(NULL, "Window Registration Failed!", "Error!", MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    // Step 2: Creating the Window
   
    hwnd = CreateWindowEx(
        WS_OVERLAPPEDWINDOW,
        g_szClassName,
        "The title of my window",
        WS_OVERLAPPEDWINDOW,
        0, 0, 240, 120,
        NULL, NULL, hInstance, NULL);

    if(hwnd == NULL)
    {
        MessageBox(NULL, "Window Creation Failed!", "Error!", MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);

    // Step 3: The Message Loop
   
    while(GetMessage(&Msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
   
    return Msg.wParam;
}

---

Never mind. It's a pointless thread. The above was the code I tried to compile, and in CreateWindowEx I put OVERLAPPEDWINDOW twice, I can't believe that I didn't notice that. It works with clientedge. But I do have a question: What is the first parameter if the fourth is the window style(s)?

Cheers.

The first one is for the extended styles and the second one is for the CreateWindow styles.

The extended window styles can be one or more of the following values:

WS_EX_ACCEPTFILES
Specifies that a window created with this style accepts drag-drop files.

WS_EX_APPWINDOW
Forces a top-level window onto the taskbar when the window is visible.

WS_EX_CLIENTEDGE
Specifies that a window has a border with a sunken edge.

WS_EX_COMPOSITED
Windows XP: Paints all descendants of a window in bottom-to-top painting order using double-buffering. For more information, see Remarks. This cannot be used if the window has a class style of either CS_OWNDC or CS_CLASSDC.

WS_EX_CONTEXTHELP
Includes a question mark in the title bar of the window. When the user clicks the question mark, the cursor changes to a question mark with a pointer. If the user then clicks a child window, the child receives a WM_HELP message. The child window should pass the message to the parent window procedure, which should call the WinHelp function using the HELP_WM_HELP command. The Help application displays a pop-up window that typically contains help for the child window.

WS_EX_CONTEXTHELP cannot be used with the WS_MAXIMIZEBOX or WS_MINIMIZEBOX styles.

WS_EX_CONTROLPARENT
The window itself contains child windows that should take part in dialog box navigation. If this style is specified, the dialog manager recurses into children of this window when performing navigation operations such as handling the TAB key, an arrow key, or a keyboard mnemonic.

WS_EX_DLGMODALFRAME
Creates a window that has a double border; the window can, optionally, be created with a title bar by specifying the WS_CAPTION style in the dwStyle parameter.

WS_EX_LAYERED
Windows 2000/XP: Creates a layered window. Note that this cannot be used for child windows. Also, this cannot be used if the window has a class style of either CS_OWNDC or CS_CLASSDC.

WS_EX_LAYOUTRTL
Arabic and Hebrew versions of Windows 98/Me, Windows 2000/XP: Creates a window whose horizontal origin is on the right edge. Increasing horizontal values advance to the left.

WS_EX_LEFT
Creates a window that has generic left-aligned properties. This is the default.

WS_EX_LEFTSCROLLBAR
If the shell language is Hebrew, Arabic, or another language that supports reading order alignment, the vertical scroll bar (if present) is to the left of the client area. For other languages, the style is ignored.

WS_EX_LTRREADING
The window text is displayed using left-to-right reading-order properties. This is the default.

WS_EX_MDICHILD
Creates a multiple-document interface (MDI) child window.

WS_EX_NOACTIVATE
Windows 2000/XP: A top-level window created with this style does not become the foreground window when the user clicks it. The system does not bring this window to the foreground when the user minimizes or closes the foreground window.
To activate the window, use the SetActiveWindow or SetForegroundWindow function.

The window does not appear on the taskbar by default. To force the window to appear on the taskbar, use the WS_EX_APPWINDOW style.

WS_EX_NOINHERITLAYOUT
Windows 2000/XP: A window created with this style does not pass its window layout to its child windows.

WS_EX_NOPARENTNOTIFY
Specifies that a child window created with this style does not send the WM_PARENTNOTIFY message to its parent window when it is created or destroyed.

WS_EX_OVERLAPPEDWINDOW
Combines the WS_EX_CLIENTEDGE and WS_EX_WINDOWEDGE styles.

WS_EX_PALETTEWINDOW
Combines the WS_EX_WINDOWEDGE, WS_EX_TOOLWINDOW, and WS_EX_TOPMOST styles.

WS_EX_RIGHT
The window has generic "right-aligned" properties. This depends on the window class. This style has an effect only if the shell language is Hebrew, Arabic, or another language that supports reading-order alignment; otherwise, the style is ignored.
Using the WS_EX_RIGHT style for static or edit controls has the same effect as using the SS_RIGHT or ES_RIGHT style, respectively. Using this style with button controls has the same effect as using BS_RIGHT and BS_RIGHTBUTTON styles.

WS_EX_RIGHTSCROLLBAR
Vertical scroll bar (if present) is to the right of the client area. This is the default.

WS_EX_RTLREADING
If the shell language is Hebrew, Arabic, or another language that supports reading-order alignment, the window text is displayed using right-to-left reading-order properties. For other languages, the style is ignored.

WS_EX_STATICEDGE
Creates a window with a three-dimensional border style intended to be used for items that do not accept user input.

WS_EX_TOOLWINDOW
Creates a tool window; that is, a window intended to be used as a floating toolbar. A tool window has a title bar that is shorter than a normal title bar, and the window title is drawn using a smaller font. A tool window does not appear in the taskbar or in the dialog that appears when the user presses ALT+TAB. If a tool window has a system menu, its icon is not displayed on the title bar. However, you can display the system menu by right-clicking or by typing ALT+SPACE.

WS_EX_TOPMOST
Specifies that a window created with this style should be placed above all non-topmost windows and should stay above them, even when the window is deactivated. To add or remove this style, use the SetWindowPos function.

WS_EX_TRANSPARENT
Specifies that a window created with this style should not be painted until siblings beneath the window (that were created by the same thread) have been painted. The window appears transparent because the bits of underlying sibling windows have already been painted.

To achieve transparency without these restrictions, use the SetWindowRgn function.

WS_EX_WINDOWEDGE
Specifies that a window has a border with a raised edge.

My Im in a good mood tonight. :D

Never realized that there was such a big list. Thanks for the info, and Queatrix, cheers for your descriptions. The list will be very handy in future. :D.

EDIT:

Ok, now I have another question. I know the persistence in my inquisitivity is annoying, but it seemed pointless to make a new thread. It concerns the famous 'I want to disable window movement,' problem. I've searched the boards, and many have told others to handle WM_MOVE, and position the window using SetWindowPos(). But this creates an annoying flickering effect. I was wondering if there's a 'cleaner' way to do this.

Appriciate any help you could provide.
Cheers

I think it was laserlight who posted something like;

Code:

---

  case WM_SYSCOMMAND:

            if(wParam==SC_MOVE)
              {
              break;
              }

---

I can't precisely remember. I do recall running across it somewhere on the boards -

That only prevents use of the system/window menu 'Move' option - it won't prevent dragging.

Code:

---

case WM_SYSCOMMAND:
  {
  /*block attempts to move window by:*/
  if (wParam == (SC_MOVE | HTCAPTION) || /*dragging caption with mouse*/
      wParam == SC_MOVE)                /*window/system menu 'Move' command*/
    {
    return 0;
    }
  return DefWindowProc(hwnd,WM_SYSCOMMAND,wParam,lParam);
  }

---

Exelent. That is really helpful code and replies.
Thanks everyone!