how does main window repaint its child windows

[z23]

a newbie question:
I wander if there is a callback procedure attached to the child window,and this procedure is supplyed by system.
for example ,a button ,how does the main window procedure receive the COMMAND message when user has clicked on this child window.
thx

[hutch--]

Hi z23,

Welcome on board. The basics are that every window has a callback attached to it that the OS sends messages to, controls included and generally the control handles its own redraw updates on a demand basis. Depending on the design of the control, it sends various user input messages to its parent window and in the case of a common command like WM_COMMAND, it is passed as a message to the parent where you can write code to respond to it.

[z23]

i see.
thanks hutch.
I am so glad to read your answer.
As a student from china,I found this is a good place to communicate with each other and learn from each other.

.....just with no confidence about my english...

[hutch--]

Have no fear about your English, everyone is welcome here and we have people from around the world so its no big deal.