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 CREATESTRUCT

The CREATESTRUCT structure defines the initialization parameters passed to the window procedure of an application. These members are identical to the parameters of the CreateWindowEx function.

Syntax

    typedef struct tagCREATESTRUCT { 
      LPVOID        lpCreateParams; 
      HINSTANCE     hInstance; 
      HMENU         hMenu; 
      HWND          hwndParent; 
      int           cy; 
      int           cx; 
      int           y; 
      int           x; 
      LONG          style; 
      LPCTSTR       lpszName; 
      LPCTSTR       lpszClass; 
      DWORD         dwExStyle; 
    } CREATESTRUCT; 

Memebers:

• lpCreateParams
  Long pointer to additional data that can be used to create the window. If the window is being created as a result of a call to the CreateWindow or CreateWindowEx function, this member contains the value of the lpParam parameter specified in the function call. If the window being created is an MDI window, this member contains a pointer to an MDICREATESTRUCT structure. Windows NT/2000 or later: If the window is being created from a dialog template, this member is the address of a SHORT value that specifies the size, in bytes, of the window creation data. The value is immediately followed by the creation data. For more information, see the following Remarks section.
• hInstance
  Handle to the module that owns the new window.
• hMenu
  Handle to the menu to be used by the new window.
• hwndParent
  Handle to the parent window, if the window is a child window. If the window is owned, this member identifies the owner window. If the window is not a child or owned window, this member is NULL.
• cy
  Specifies the height of the new window, in pixels.
• cx
  Specifies the width of the new window, in pixels.
• y
  Specifies the y-coordinate of the upper left corner of the new window. If the new window is a child window, coordinates are relative to the parent window. Otherwise, the coordinates are relative to the screen origin.
• x
  Specifies the x-coordinate of the upper left corner of the new window. If the new window is a child window, coordinates are relative to the parent window. Otherwise, the coordinates are relative to the screen origin.
• style
  Specifies the style for the new window.
• lpszName
  Long pointer to a null-terminated string that specifies the name of the new window.
• lpszClass
  Long pointer to a null-terminated string that specifies the class name of the new window.
• dwExStyle
  Specifies the extended style for the new window.

Remarks

Windows NT/2000 or later: You should access the data represented by the lpCreateParams member using a pointer that has been declared using the UNALIGNED type, because the pointer may not be DWORD aligned. This is demonstrated in the following code example:

    typedef struct tagMyData { 
    // Define creation data here. 
    } MYDATA; 

    typedef struct tagMyDlgData { 
        SHORT cbExtra; 
        MYDATA myData; 
    } MYDLGDATA, UNALIGNED *PMYDLGDATA; 

    PMYDLGDATA pMyDlgdata = (PMYDLGDATA) (((LPCREATESTRUCT) lParam)->lpCreateParams); 

Requirements

• Windows NT/2000 or later: Requires Windows NT 3.1 or later.
• Windows 95/98/Me: Requires Windows 95 or later.
• Header: Declared in Winuser.h; include Windows.h.
• Unicode: Declared as Unicode and ANSI structures.

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time