The TB_BUTTONSTRUCTSIZE message specifies the size of the TBBUTTON structure.
wParam = (WPARAM) cb;
lParam = 0;
Parameters
cb
Size, in bytes, of the TBBUTTON structure.
The system uses the size to determine which version of the common control dynamic-link library (DLL) is being used.
If an application uses the CreateWindowEx function to create the toolbar, the application must send this message to the toolbar before sending the TB_ADDBITMAP or TB_ADDBUTTONS message. The CreateToolBarEx function automatically sends TB_BUTTONSTRUCTSIZE, and the size of the TBBUTTON structure is a parameter of the function.
Return Values
No return value.
See Also