The WM_STYLECHANGING message is sent to a window when the SetWindowLong function is about to change one or more of the window's styles.
WM_STYLECHANGING
wStyleType = wParam; // extended or nonextended styles
lpss = (LPSTYLESTRUCT) lParam; // structure containing new styles
Parameters
wStyleType
Value of wParam. Specifies whether the window's extended or nonextended styles have changed. This parameter can be a combination of the following values:
| Value | Meaning |
| GWL_EXSTYLE | The window's extended styles are changing. |
| GWL_STYLE | The window's nonextended styles are changing. |
lpss
Value of lParam. Points to a STYLESTRUCT structure that contains the proposed new styles for the window. An application can examine the styles and, if necessary, change them.
Return Values
An application should return zero if it processes this message.
See Also