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This function retrieves the specified 32-bit (long) value from the WNDCLASSstructure associated with the specified window.
DWORD GetClassLong( HWND hWnd , int nIndex );
Parameters
Value | Description |
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GCW_ATOM | Retrieves an ATOMvalue that uniquely identifies the window class. This is the same atom that the RegisterClassfunction returns. |
GCL_CBCLSEXTRA | Retrieves the size, in bytes, of the extra memory associated with the class. |
GCL_CBWNDEXTRA | Retrieves the size, in bytes, of the extra window memory associated with each window in the class. For information on how to access this memory, see GetWindowLong. |
GCL_HBRBACKGROUND | Retrieves a handle to the background brush associated with the class. |
GCL_HCURSOR | Retrieves a handle to the cursor associated with the class. |
GCL_HICON | Retrieves a handle to the icon associated with the class. |
GCL_HICONSM | Retrieves a handle to the small icon associated with the class. |
GCL_HMODULE | Retrieves a handle to the module that registered the class. |
GCL_MENUNAME | Retrieves the address of the menu name string. The string identifies the menu resource associated with the class. |
GCL_STYLE | Retrieves the window-class style bits. |
GCL_WNDPROC | Retrieves the address of the window procedure associated with the class. |
Return Values
The requested 32-bit value indicates success. Zero indicates failure. To get extended error information, call GetLastError.
Remarks
The nIndexparameter is a byte offset but must be a multiple of 4 bytes. Windows CE does not support unaligned access.
The only values supported for the nIndexparameter are GCL_HICON and GCL_STYLE.
If you are using the Windows CE Iconcurs component, which supports mouse cursors on appropriate target platforms, you can also use the GCL_HCURSOR value in the nIndexparameter.
Windows CE versions that support mouse cursors include the Iconcurs and Mcursor components rather than the Icon and Cursor components.
Reserve extra class memory by specifying a nonzero value in the cbClsExtramember of the WNDCLASSstructure used with the RegisterClassfunction.
Requirements
Runs on | Versions | Defined in | Include | Link to |
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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.
See Also
GetLastError, GetWindowLong, RegisterClass, SetClassLong, WNDCLASS