The WM_CREATE message is sent when an application requests that a window be created by calling the CreateWindowEx or CreateWindow function. The window procedure of the new window receives this message after the window is created, but before the window becomes visible. The message is sent before the CreateWindowEx or CreateWindow function returns.
WM_CREATE
lpcs = (LPCREATESTRUCT) lParam; // structure with creation data
Parameters
lParam
Value of lParam. Points to a CREATESTRUCT structure that contains information about the window being created. The members of CREATESTRUCT are identical to the parameters of the CreateWindowEx function.
Return Values
If an application processes this message, it should return 0 to continue creation of the window. If the application returns -1, the window is destroyed and the CreateWindowEx or CreateWindow function returns a NULL handle.
See Also