CreateWindow

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This 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. This function also specifies the window's parent.

HWND
CreateWindow( LPCTSTR
lpClassName
, LPCTSTR
lpWindowName
, DWORD
dwStyle
, int
x
, int
y
, int
nWidth
, int
nHeight
, HWND
hWndParent
, HMENU
hMenu
, HANDLE
hInstance
, PVOID
lpParam
);

Parameters

lpClassName

Long pointer to a null-terminated string or an integer atom. If this parameter is an atom, it must be a global atom created by a previous call to the RegisterClassfunction. The atom, a 16-bit value less than 0xC000, must be in the low-order word of lpClassName; the high-order word must be zero.

If lpClassNameis a string, it specifies the window class name. The class name can be any name registered with the RegisterClassfunction or any of the predefined control-class names. For a complete list, see the Remarks section.

lpWindowName

Long pointer to a null-terminated string that specifies the window name.

If the window style specifies a title bar, the window title pointed to by lpWindowNameis displayed in the title bar. When using CreateWindowto create controls, such as buttons, check boxes, and static controls, use lpWindowNameto specify the text of the control.

dwStyle

Specifies the style of the window being created. This parameter can be a combination of the following window styles, plus the control styles indicated in the Remarks section.

Value	Description
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_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_PAINTmessage, 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_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_SIZEBOX	Creates a window that has a sizing border. Same as the WS_THICKFRAME style.
WS_SYSMENU	Creates a window that has a Close (X)button in the non-client area.
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.

x

Specifies the initial horizontal position of the window. For an overlapped or pop-up window, the xparameter is the initial x-coordinate of the window's upper-left corner, in screen coordinates. For a child window, xis the x-coordinate of the upper-left corner of the window relative to the upper-left corner of the parent window's client area.

If this parameter is set to CW_USEDEFAULT, the system selects the default position for the window's upper-left corner and ignores the yparameter. CW_USEDEFAULT is valid only for overlapped windows; if it is specified for a pop-up or child window, the xand yparameters are set to zero.

y

Specifies the initial vertical position of the window. For an overlapped or pop-up window, the yparameter is the initial y-coordinate of the window's upper-left corner, in screen coordinates. For a child window, yis the initial y-coordinate of the upper-left corner of the child window relative to the upper-left corner of the parent window's client area. For a list box, yis the initial y-coordinate of the upper-left corner of the list box's client area relative to the upper-left corner of the parent window's client area.

If an overlapped window is created with the WS_VISIBLE style bit set and the xparameter is set to CW_USEDEFAULT, the system ignores the yparameter.

nWidth

Specifies the width, in device units, of the window. For overlapped windows, nWidthis either the window's width, in screen coordinates, or CW_USEDEFAULT. If nWidthis CW_USEDEFAULT, the system selects a default width and height for the window; the default width extends from the initial x-coordinate to the right edge of the screen, and the default height extends from the initial y-coordinate to the top of the icon area. CW_USEDEFAULT is valid only for overlapped windows; if CW_USEDEFAULT is specified for a pop-up or child window, nWidthand nHeightare set to zero.

nHeight

Specifies the height, in device units, of the window. For overlapped windows, nHeightis the window's height, in screen coordinates. If nWidthis set to CW_USEDEFAULT, the system ignores nHeight.

hWndParent

Handle to the parent or owner window of the window being created. To create a child window or an owned window, supply a valid window handle. This parameter is optional for pop-up windows.

hMenu

Handle to a menu, or specifies a child-window identifier depending on the window style. For an overlapped or pop-up window, hMenuidentifies the menu to be used with the window; it can be NULL if the class menu is to be used. For a child window, hMenuspecifies the child-window identifier, an integer value used by a dialog box control to notify its parent about events. The application determines the child-window identifier; it must be unique for all child windows with the same parent window.

hInstance

Handle to the instance of the module to be associated with the window.

lpParam

Long pointer to a value to be passed to the window through the CREATESTRUCTstructure passed in the lParamparameter the WM_CREATEmessage.

Return Values

A handle to the new window indicates success. NULL indicates failure. To get extended error information, call GetLastError.

Remarks

The CreateWindowfunction does not support the WM_NCDESTROY or the WM_PARENTNOTIFY message.

CreateWindowis implemented as a macro. It is defined as CreateWindowEx, but with the dwExStyleparameter set to 0L.

Menu bars are not supported. The hMenuparameter must be NULL, unless it is used as a child-window identifier.

The MDICLIENT window class is not supported.

The dwStyleparameter can be a combination of the window styles and control styles documented in Window and Message Box Stylesand Control Styles.

The following dwStyleflags are not supported for Windows CE:

WS_CHILDWINDOW	WS_ICONIC
WS_POPUPWINDOW

The following dwStyleflags are not supported for controls and dialog boxes:

Unsupported button styles	Unsupported static control styles
BS_LEFTTEXT	SS_BLACKFRAME
BS_TEXT	SS_BLACKRECT
BS_USERBUTTON	SS_GRAYFRAME
Unsupported combo box styles	SS_GRAYRECT
CBS_OWNERDRAWFIXED	SS_METAPICT
CBS_OWNERDRAWVARIABLE	SS_REALSIZEIMAGE
CBS_SIMPLE	SS_RIGHTIMAGE
Unsupported list box control styles	SS_RIGHTJUST
LBS_NODATA	SS_SIMPLE
LBS_OWNERDRAWFIXED	SS_SUNKEN
LBS_OWNERDRAWVARIABLE	SS_WHITEFRAME
LBS_STANDARD	SS_WHITERECT
Unsupported scroll bar styles	Unsupported dialog box styles
SBS_BOTTOMALIGN	DS_ABSALIGN
SBS_RIGHTALIGN	DS_CENTERMOUSE
SBS_SIZEBOXBOTTOMRIGHTALIGN	DS_CONTEXTHELP
SBS_SIZEGRIP	DS_FIXEDSYS
	DS_NOFAILCREATE
	DS_NOIDLEMSG
	DS_SYSMODAL

You can use the BS_OWNERDRAW style as a substitute for the BS_USERBUTTON style.

Combine the BS_MULTILINE style with the BS_PUSHBUTTON style to wrap text on a button.

You can use the SS_LEFT or SS_LEFTNOWORDWRAP style instead of the SS_SIMPLE style for static controls.

All windows implicitly have the WS_CLIPSIBLINGS and WS_CLIPCHILDREN styles.

Windows CE version 1.0 does not support owned windows, except for dialog boxes. If the hwndParentparameter is not NULL, the window is implicitly given the WS_CHILD style.

Windows CE version 1.0 does not support menu bars.

For Windows CE versions 2.10 and later, if nWidthand nHeightare set to CW_USEDEFAULT, the child window has dimensions of 0 x 0.

Before returning, CreateWindowsends a WM_CREATEmessage to the window procedure. For overlapped, pop-up, and child windows, CreateWindowsends WM_CREATE messages to the window. The lParamparameter of the WM_CREATE message contains a pointer to a CREATESTRUCTstructure. If the WS_VISIBLE style is specified, CreateWindowsends the window all the messages required to activate and show the window.

The following predefined control classes can be specified in the lpClassNameparameter. Note the corresponding control styles you can use in the dwStyleparameter.

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 about buttons and the styles you can specify in the dwStyleparameter, see Control 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 about edit controls and the styles you can specify in the dwStyleparameter, see 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 about list boxes and the styles you can specify in the dwStyleparameter, see Control 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.

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.

RICHEDIT_CLASS

Designates a Rich Edit version 2.0 control. This control lets the user view and edit text with character and paragraph formatting, and can include embedded COM objects. Windows CE for Pocket PC does not support this control class.

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 about scroll bars and the styles you can specify in the dwStyleparameter, see 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 about static controls and the styles you can specify in the dwStyleparameter, see Creating Controls.

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.

Requirements

Runs on	Versions	Defined in	Include	Link to
Windows CE OS	1.0 and later	Winuser.h

Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.