windowclass api

GetClassInfoEx  检索返回一个class信息

BOOL WINAPI GetClassInfoEx(  __in_opt  HINSTANCE hinst,  __in      LPCTSTR lpszClass,  //class name  __out     LPWNDCLASSEX lpwcx  //指向class Structure);

GetClassLongEx 根据nIndex返回class信息

DWORD WINAPI GetClassLongEx(  __in  HWND hWnd,  __in  int nIndex);

ValueMeaning

GCW_ATOM

-32

Retrieves an ATOM value that uniquely identifies the window class. This is the same atom that the RegisterClassEx function returns.

GCL_CBCLSEXTRA

-20

Retrieves the size, in bytes, of the extra memory associated with the class.

GCL_CBWNDEXTRA

-18

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

-10

Retrieves a handle to the background brush associated with the class.

GCL_HCURSOR

-12

Retrieves a handle to the cursor associated with the class.

GCL_HICON

-14

Retrieves a handle to the icon associated with the class.

GCL_HICONSM

-34

Retrieves a handle to the small icon associated with the class.

GCL_HMODULE

-16

Retrieves a handle to the module that registered the class.

GCL_MENUNAME

-8

Retrieves the address of the menu name string. The string identifies the menu resource associated with the class.

GCL_STYLE

-26

Retrieves the window-class style bits.

GCL_WNDPROC

-24

Retrieves the address of the window procedure, or a handle representing the address of the window procedure. You must use the CallWindowProc function to call the window procedure.

GetClassLongPtr()   可用在32至64位，在64位上调用GetclassLong

ULONG_PTR WINAPI GetClassLongPtr(  __in  HWND hWnd,  __in  int nIndex);

GetClassName  返回值是成功复制到缓冲区的字符数，不包括null

int WINAPI GetClassName(  __in   HWND hWnd,  __out  LPTSTR lpClassName,  __in   int nMaxCount);