WNDCLASS Structure
Type WNDCLASS
style As Long
lpfnWndProc As Long
cbClsExtra As Long
cbWndExtra As Long
hInstance As Long
hIcon As Long
hCursor As Long
hbrBackground As Long
lpszMenuName As String
lpszClassName As String
End Type
Description & Usage
The WNDCLASS structure holds most of the information defining a window class. This information is used by any windows which belong to the class. The only item which this structure does not hold is a handle to the class's small icon. (The more advanced WNDCLASSEX structure does.)
Visual Basic-Specific Issues
None.
Data Members
- style
- A combination of the following flags specifying various styles to give to windows which belong to the class:
- CS_BYTEALIGNCLIENT
- Align the window's client area horizontally on the byte boundary.
- CS_BYTEALIGNWINDOW
- Align the window horizontally on the byte boundary.
- CS_CLASSDC
- Have all windows belonging to the class use a single shared device context used by all threads.
- CS_DBLCLKS
- Send a double-click message to the window procedure whenever the user double-clicks the mouse inside the window.
- CS_GLOBALCLASS
- Allow any application to create a window from this class. (If this flag is not specified, only the instance registering the class is allowed to use it.) The window class must be defined in a dynamic link library loaded at startup.
- CS_HREDRAW
- Redraw the entire window if a movement or size change alters the width of the window's client area.
- CS_NOCLOSE
- Disable the Close command on the window's menu.
- CS_OWNDC
- Give each window belonging to the class its own device context.
- CS_PARENTDC
- Set the clipping region of a child window equal to that of its parent window, allowing the child to draw on the parent.
- CS_SAVEBITS
- Save as a bitmap the portion of the screen image obscured by the window. This bitmap is then used to redraw the screen when the window is removed. Using this consumes more resources.
- CS_VREDRAW
- Redraw the entire window if a movement or size change alters the height of the window's client area.
- lpfnWndProc
- A pointer to the WindowProc hook function used for the window procedure which processes all of messages of each window belonging to the class.
- cbClsExtra
- The number of extra bytes to allocate following the window class structure for additional storage.
- cbWndExtra
- The number of extra bytes to allocate following the window instance structure for additional storage.
- hInstance
- A handle to the instance which contains the window procedure for the class.
- hIcon
- A handle to the window class's icon.
- hCursor
- A handle to the window class's cursor.
- hbrBackground
- A handle to the brush used to fill the window's background area. This can also be one of the following flags specifying the system color to use as the background color:
- COLOR_ACTIVEBORDER
- The color of an active window's border.
- COLOR_ACTIVECAPTION
- The color of an active window's caption.
- COLOR_APPWORKSPACE
- The color of an application's workspace.
- COLOR_BACKGROUND
- The color of the desktop background.
- COLOR_BTNFACE
- The color of a button's face.
- COLOR_BTNHIGHLIGHT
- The color of a button's highlight area.
- COLOR_BTNSHADOW
- The color of a button's shadow area.
- COLOR_BTNTEXT
- The color of a button's text.
- COLOR_CAPTIONTEXT
- The color of an active window's caption area's text.
- COLOR_GRAYTEXT
- The color of grayed-out text.
- COLOR_HIGHLIGHT
- The color of a highlight.
- COLOR_HIGHLIGHTTEXT
- The color of text in a highlight.
- COLOR_INACTIVEBORDER
- The color of an inactive window's border.
- COLOR_INACTIVECAPTION
- The color of an inactive window's caption.
- COLOR_INACTIVECAPTIONTEXT
- The color of an inactive window's caption area's text.
- COLOR_MENU
- The color of a menu.
- COLOR_MENUTEXT
- The color of a menu's text.
- COLOR_SCROLLBAR
- The color of a scrollbar.
- COLOR_WINDOW
- The color of a window.
- COLOR_WINDOWFRAME
- The color of a window's frame.
- COLOR_WINDOWTEXT
- The color of a window's text.
- lpszMenuName
- The name of the window class's menu resource, if any.
- lpszClassName
- The name of the window class.
Constant Definitions
Const CS_BYTEALIGNCLIENT = &H1000
Const CS_BYTEALIGNWINDOW = &H2000
Const CS_CLASSDC = &H40
Const CS_DBLCLKS = &H8
Const CS_HREDRAW = &H2
Const CS_NOCLOSE = &H200
Const CS_OWNDC = &H20
Const CS_PARENTDC = &H80
Const CS_SAVEBITS = &H800
Const CS_VREDRAW = &H1
Const COLOR_ACTIVEBORDER = 10
Const COLOR_ACTIVECAPTION = 2
Const COLOR_APPWORKSPACE = 12
Const COLOR_BACKGROUND = 1
Const COLOR_BTNFACE = 15
Const COLOR_BTNHIGHLIGHT = 20
Const COLOR_BTNSHADOW = 16
Const COLOR_BTNTEXT = 18
Const COLOR_CAPTIONTEXT = 9
Const COLOR_GRAYTEXT = 17
Const COLOR_HIGHLIGHT = 13
Const COLOR_HIGHLIGHTTEXT = 14
Const COLOR_INACTIVEBORDER = 11
Const COLOR_INACTIVECAPTION = 3
Const COLOR_INACTIVECAPTIONTEXT = 19
Const COLOR_MENU = 4
Const COLOR_MENUTEXT = 7
Const COLOR_SCROLLBAR = 0
Const COLOR_WINDOW = 5
Const COLOR_WINDOWFRAME = 6
Const COLOR_WINDOWTEXT = 8
Used By
GetClassInfo, RegisterClass
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Last Modified: August 22, 1999
This page is copyright © 1999 Paul Kuliniewicz.
Copyright Information Revised October 29, 2000
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