The CreateWindow function creates an overlapped, pop-up, or child window. It specifies the window class, window title, window style, and (optionally) the initial position and size of the window. The function also specifies the window's parent or owner, if any, and the window's menu.
To use extended styles in addition to the styles supported by CreateWindow, use the CreateWindowEx function instead of using CreateWindow.
HWND CreateWindow(
LPCTSTR lpClassName, // pointer to registered class name
LPCTSTR lpWindowName, // pointer to window name
DWORD dwStyle, // window style
int x, // horizontal position of window
int y, // vertical position of window
int nWidth, // window width
int nHeight, // window height
HWND hWndParent, // handle to parent or owner window
HMENU hMenu, // handle to menu or child-window identifier
HANDLE hInstance, // handle to application instance
LPVOID lpParam // pointer to window-creation data
);
If lpClassName is a string, it specifies the window class name. The class name can be any name registered with the RegisterClassEx function or any of the predefined control-class names. For a complete list, see the Remarks section.
If the window style specifies a title bar, the window title pointed to by lpWindowName is displayed in the title bar. When using CreateWindow to create controls, such as buttons, check boxes, and static controls, use lpWindowName to specify the text of the control.
Style | Meaning |
---|---|
WS_BORDER | Creates a window that has a thin-line border. |
WS_CAPTION | Creates a window that has a title bar (includes the WS_BORDER style). |
WS_CHILD | Creates a child window. This style cannot be used with the WS_POPUP style. |
WS_CHILDWINDOW | Same as the WS_CHILD style. |
WS_CLIPCHILDREN | Excludes the area occupied by child windows when drawing occurs within the parent window. This style is used when creating the parent window. |
WS_CLIPSIBLINGS | Clips child windows relative to each other; that is, when a particular child window receives a WM_PAINT message, the WS_CLIPSIBLINGS style clips all other overlapping child windows out of the region of the child window to be updated. If WS_CLIPSIBLINGS is not specified and child windows overlap, it is possible, when drawing within the client area of a child window, to draw within the client area of a neighboring child window. |
WS_DISABLED | Creates a window that is initially disabled. A disabled window cannot receive input from the user. |
WS_DLGFRAME | Creates a window that has a border of a style typically used with dialog boxes. A window with this style cannot have a title bar. |
WS_GROUP | Specifies the first control of a group of controls. The group consists of this first control and all controls defined after it, up to the next control with the WS_GROUP style. The first control in each group usually has the WS_TABSTOP style so that the user can move from group to group. The user can subsequently change the keyboard focus from one control in the group to the next control in the group by using the direction keys. |
WS_HSCROLL | Creates a window that has a horizontal scroll bar. |
WS_ICONIC | Creates a window that is initially minimized. Same as the WS_MINIMIZE style. |
WS_MAXIMIZE | Creates a window that is initially maximized. |
WS_MAXIMIZEBOX | Creates a window that has a Maximize button. Cannot be combined with the WS_EX_CONTEXTHELP style. The WS_SYSMENU style must also be specified. |
WS_MINIMIZE | Creates a window that is initially minimized. Same as the WS_ICONIC style. |
WS_MINIMIZEBOX | Creates a window that has a Minimize button. Cannot be combined with the WS_EX_CONTEXTHELP style. The WS_SYSMENU style must also be specified. |
WS_OVERLAPPED | Creates an overlapped window. An overlapped window has a title bar and a border. Same as the WS_TILED style. |
WS_OVERLAPPEDWINDOW | Creates an overlapped window with the WS_OVERLAPPED, WS_CAPTION, WS_SYSMENU, WS_THICKFRAME, WS_MINIMIZEBOX, and WS_MAXIMIZEBOX styles. Same as the WS_TILEDWINDOW style. |
WS_POPUP | Creates a pop-up window. This style cannot be used with the WS_CHILD style. |
WS_POPUPWINDOW | Creates a pop-up window with WS_BORDER, WS_POPUP, and WS_SYSMENU styles. The WS_CAPTION and WS_POPUPWINDOW styles must be combined to make the window menu visible. |
WS_SIZEBOX | Creates a window that has a sizing border. Same as the WS_THICKFRAME style. |
WS_SYSMENU | Creates a window that has a window-menu on its title bar. The WS_CAPTION style must also be specified. |
WS_TABSTOP | Specifies a control that can receive the keyboard focus when the user presses the tab key. Pressing the tab key changes the keyboard focus to the next control with the WS_TABSTOP style. |
WS_THICKFRAME | Creates a window that has a sizing border. Same as the WS_SIZEBOX style. |
WS_TILED | Creates an overlapped window. An overlapped window has a title bar and a border. Same as the WS_OVERLAPPED style. |
WS_TILEDWINDOW | Creates an overlapped window with the WS_OVERLAPPED, WS_CAPTION, WS_SYSMENU, WS_THICKFRAME, WS_MINIMIZEBOX, and WS_MAXIMIZEBOX styles. Same as the WS_OVERLAPPEDWINDOW style. |
WS_VISIBLE | Creates a window that is initially visible. |
WS_VSCROLL | Creates a window that has a vertical scroll bar. |
If this parameter is set to CW_USEDEFAULT, the system selects the default position for the window's upper-left corner and ignores the y parameter. CW_USEDEFAULT is valid only for overlapped windows; if it is specified for a pop-up or child window, the x and y parameters are set to zero.
If an overlapped window is created with the WS_VISIBLE style bit set and the x parameter is set to CW_USEDEFAULT, the system ignores the y parameter.
Windows NT 5.0 and later: To create a message-only window, supply HWND_MESSAGE or a handle to an existing message-only window.
If the function succeeds, the return value is a handle to the new window.
If the function fails, the return value is NULL. To get extended error information, call GetLastError.
Before returning, CreateWindow sends a WM_CREATE message to the window procedure. For overlapped, pop-up, and child windows, CreateWindow sends WM_CREATE, WM_GETMINMAXINFO, and WM_NCCREATE messages to the window. The lParam parameter of the WM_CREATE message contains a pointer to a CREATESTRUCT structure. If the WS_VISIBLE style is specified, CreateWindow sends the window all the messages required to activate and show the window.
For information on controlling whether the Taskbar displays a button for the created window, see Visibility of Taskbar Buttons.
The following predefined control classes can be specified in the lpClassName parameter. Note the corresponding control styles you can use in the dwStyle parameter.
Class | Meaning |
---|---|
BUTTON | Designates a small rectangular child window that represents a button the user can click to turn it on or off. Button controls can be used alone or in groups, and they can either be labeled or appear without text. Button controls typically change appearance when the user clicks them. For more information, see Buttons. |
For a table of the button styles you can specify in the dwStyle parameter, see Button Styles. | |
COMBOBOX | Designates a control consisting of a list box and a selection field similar to an edit control. When using this style, an application should either display the list box at all times or enable a drop-down list box. If the list box is visible, typing characters into the selection field highlights the first list box entry that matches the characters typed. Conversely, selecting an item in the list box displays the selected text in the selection field. For more information, see Combo Boxes. |
For a table of the combo box styles you can specify in the dwStyle parameter, see Combo Box Styles. | |
EDIT | Designates a rectangular child window into which the user can type text from the keyboard. The user selects the control and gives it the keyboard focus by clicking it or moving to it by pressing the tab key. The user can type text when the edit control displays a flashing caret; use the mouse to move the cursor, select characters to be replaced, or position the cursor for inserting characters; or use the backspace key to delete characters. For more information, see Edit Controls. |
For a table of the edit control styles you can specify in the dwStyle parameter, see Edit Control Styles. | |
LISTBOX | Designates a list of character strings. Specify this control whenever an application must present a list of names, such as filenames, from which the user can choose. The user can select a string by clicking it. A selected string is highlighted, and a notification message is passed to the parent window. For more information, see List Boxes. |
For a table of the list box styles you can specify in the dwStyle parameter, see List Box Styles. | |
MDICLIENT | Designates an MDI client window. This window receives messages that control the MDI application's child windows. The recommended style bits are WS_CLIPCHILDREN and WS_CHILD. Specify the WS_HSCROLL and WS_VSCROLL styles to create an MDI client window that allows the user to scroll MDI child windows into view. For more information, see Multiple Document Interface. |
RichEdit | Designates a Rich Edit version 1.0 control. This window lets the user view and edit text with character and paragraph formatting, and can include embedded COM objects. For more information, see Rich Edit Controls. |
For a table of the rich edit control styles you can specify in the dwStyle parameter, see Rich Edit Control Styles. | |
RICHEDIT_CLASS | Designates a Rich Edit version 2.0 control. This controls let the user view and edit text with character and paragraph formatting, and can include embedded COM objects. For more information, see Rich Edit Controls. |
For a table of the rich edit control styles you can specify in the dwStyle parameter, see Rich Edit Control Styles. | |
SCROLLBAR | Designates a rectangle that contains a scroll box and has direction arrows at both ends. The scroll bar sends a notification message to its parent window whenever the user clicks the control. The parent window is responsible for updating the position of the scroll box, if necessary. For more information, see Scroll Bars. |
For a table of the scroll bar control styles you can specify in the dwStyle parameter, see Scroll Bar Control Styles. | |
STATIC | Designates a simple text field, box, or rectangle used to label, box, or separate other controls. Static controls take no input and provide no output. For more information, see Static Controls. |
For a table of the static control styles you can specify in the dwStyle parameter, see Static Control Styles. |
Windows 95: The system can support a maximum of 16,364 window handles.
Note If you specify Windows version 4.x when linking your application, its windows cannot have caption buttons unless they also have window menus. This is not a requirement if you specify Windows version 3.x when linking your application.
Windows CE: CreateWindow is implemented as a macro. It is defined as CreateWindowEx, but with the dwExStyle parameter set to 0L.
Menu bars are not supported. The hMenu parameter must be NULL, unless it is used as a child-window identifier.
The MDICLIENT window class is not supported.
The dwStyle parameter can be a combination of the window styles and control styles documented in:
Dialog Boxes
Windows
Controls
The following dwStyle flags are not supported for windows:
WS_CHILDWINDOW | WS_ICONIC |
WS_MAXIMIZE | WS_MAXIMIZEBOX |
WS_MINIMIZE | WS_MINIMIZEBOX |
WS_OVERLAPPEDWINDOW | WS_POPUPWINDOW |
WS_SIZEBOX | WS_THICKFRAME |
WS_TILED | WS_TILEDWINDOW |
The following dwStyle flags are not supported for controls and dialog boxes:
Unsupported button styles | Unsupported static control styles |
BS_LEFTTEXT | SS_BLACKFRAME |
BS_MULTILINE | SS_GRAYFRAME |
BS_TEXT | SS_METAPICT |
BS_USERBUTTON | SS_SIMPLE |
Unsupported combo box styles | SS_WHITERECT |
CBS_OWNERDRAWFIXED | SS_BLACKRECT |
CBS_OWNERDRAWVARIABLE | SS_GRAYRECT |
CBS_SIMPLE | SS_RIGHTIMAGE |
Unsupported list box control styles | SS_WHITEFRAME |
LBS_NODATA | Unsupported dialog box styles |
LBS_OWNERDRAWFIXED | DS_ABSALIGN |
LBS_OWNERDRAWVARIABLE | DS_CENTERMOUSE |
LBS_STANDARD | DS_CONTEXTHELP |
Unsupported scroll bar styles | DS_FIXEDSYS |
SBS_BOTTOMALIGN | DS_NOFAILCREATE |
SBS_RIGHTALIGN | DS_NOIDLEMSG |
SBS_SIZEBOXBOTTOMRIGHTALIGN | DS_SYSMODAL |
SBS_SIZEGRIP |
You can use the BS_OWNERDRAW style as a substitute for the BS_USERBUTTON style.
You can use the SS_LEFT or SS_LEFTNOWORDWRAP style instead of the SS_SIMPLE style for static controls..
The MDICLIENT window class is not supported.
All windows implicitly have the WS_CLIPSIBLINGS and WS_CLIPCHILDREN styles.
Windows CE 1.0 does not support owned windows, except for dialog boxes. If the hwndParent parameter is not NULL, the window is implicitly given the WS_CHILD style.
Windows CE version 1.0 does not support menu bars.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Import Library: Use user32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT.
Windows Overview, Window Functions, CLIENTCREATESTRUCT, CREATESTRUCT, CreateWindowEx, GlobalAddAtom, RegisterClassEx, WM_COMMAND, WM_CREATE, WM_GETMINMAXINFO, WM_NCCREATE, WM_PAINT