LPCTSTR AFXAPI AfxRegisterWndClass( UINT nClassStyle, HCURSOR hCursor = 0, HBRUSH hbrBackground = 0, HICON hIcon = 0 );
Return Value
A null-terminated string containing the class name. You can pass this class name to the Create member function in CWnd or other CWnd-derived classes to create a window. The name is generated by the Microsoft Foundation Class Library.
Note The return value is a pointer to a static buffer. To save this string, assign it to a CString variable.
Parameters
nClassStyle
Specifies the Windows class style or combination of styles, created by using the bitwise-OR (|) operator, for the window class. For a list of class styles, see theWNDCLASS structure in the Win32 SDK documentation. If NULL, the defaults will be set as follows:
Sets the mouse style to CS_DBLCLKS, which sends double-click messages to the window procedure when the user double-clicks the mouse.
Sets the arrow cursor style to the Windows standard IDC_ARROW.
Sets the background brush to NULL, so the window will not erase its background.
Sets the icon to the standard, waving-flag Windows logo icon.
hCursor
Specifies a handle to the cursor resource to be installed in each window created from the window class. If you use the default of 0, you will get the standard IDC_ARROW cursor.
hbrBackground
Specifies a handle to the brush resource to be installed in each window created from the window class. If you use the default of 0, you will have a NULL background brush, and your window will, by default, not erase its background while processingWM_ERASEBKGND.
hIcon
Specifies a handle to the icon resource to be installed in each window created from the window class. If you use the default of 0, you will get the standard, waving-flag Windows logo icon.
Remarks
The Microsoft Foundation Class Library automatically registers several standard window classes for you. Call this function if you want to register your own window classes.
The name registered for a class by AfxRegisterWndClass depends solely on the parameters. If you call AfxRegisterWndClass multiple times with identical parameters, it only registers a class on the first call. Subsequent calls to AfxRegisterWndClass with identical parameters simply return the already-registered classname.
If you call AfxRegisterWndClass for multiple CWnd-derived classes with identical parameters, instead of getting a separate window class for each class, each class shares the same window class. This can cause problems if the CS_CLASSDC class style is used. Instead of multiple CS_CLASSDC window classes, you end up with one CS_CLASSDC window class, and all C++ windows that use that class share the same DC. To avoid this problem, call AfxRegisterClass to register the class.
Example
CString strMyClass;
// load stock cursor, brush, and icon for
// my own window class
try
{
strMyClass = AfxRegisterWndClass(
CS_VREDRAW | CS_HREDRAW,
::LoadCursor(NULL, IDC_ARROW),
(HBRUSH) ::GetStockObject(WHITE_BRUSH),
::LoadIcon(NULL, IDI_APPLICATION));
}
catch (CResourceException* pEx)
{
AfxMessageBox(
_T("Couldn't register class! (Already registered?)"));
pEx->Delete();
}
Return Value
A null-terminated string containing the class name. You can pass this class name to the Create member function in CWnd or other CWnd-derived classes to create a window. The name is generated by the Microsoft Foundation Class Library.
Note The return value is a pointer to a static buffer. To save this string, assign it to a CString variable.
Parameters
nClassStyle
Specifies the Windows class style or combination of styles, created by using the bitwise-OR (|) operator, for the window class. For a list of class styles, see theWNDCLASS structure in the Win32 SDK documentation. If NULL, the defaults will be set as follows:
Sets the mouse style to CS_DBLCLKS, which sends double-click messages to the window procedure when the user double-clicks the mouse.
Sets the arrow cursor style to the Windows standard IDC_ARROW.
Sets the background brush to NULL, so the window will not erase its background.
Sets the icon to the standard, waving-flag Windows logo icon.
hCursor
Specifies a handle to the cursor resource to be installed in each window created from the window class. If you use the default of 0, you will get the standard IDC_ARROW cursor.
hbrBackground
Specifies a handle to the brush resource to be installed in each window created from the window class. If you use the default of 0, you will have a NULL background brush, and your window will, by default, not erase its background while processingWM_ERASEBKGND.
hIcon
Specifies a handle to the icon resource to be installed in each window created from the window class. If you use the default of 0, you will get the standard, waving-flag Windows logo icon.
Remarks
The Microsoft Foundation Class Library automatically registers several standard window classes for you. Call this function if you want to register your own window classes.
The name registered for a class by AfxRegisterWndClass depends solely on the parameters. If you call AfxRegisterWndClass multiple times with identical parameters, it only registers a class on the first call. Subsequent calls to AfxRegisterWndClass with identical parameters simply return the already-registered classname.
If you call AfxRegisterWndClass for multiple CWnd-derived classes with identical parameters, instead of getting a separate window class for each class, each class shares the same window class. This can cause problems if the CS_CLASSDC class style is used. Instead of multiple CS_CLASSDC window classes, you end up with one CS_CLASSDC window class, and all C++ windows that use that class share the same DC. To avoid this problem, call AfxRegisterClass to register the class.
Example
CString strMyClass;
// load stock cursor, brush, and icon for
// my own window class
try
{
strMyClass = AfxRegisterWndClass(
CS_VREDRAW | CS_HREDRAW,
::LoadCursor(NULL, IDC_ARROW),
(HBRUSH) ::GetStockObject(WHITE_BRUSH),
::LoadIcon(NULL, IDI_APPLICATION));
}
catch (CResourceException* pEx)
{
AfxMessageBox(
_T("Couldn't register class! (Already registered?)"));
pEx->Delete();
}
