What does this:
I have a client server mechanism that works fine on many platforms but he isnt built with QT.
have to do with this:
I now have a function called Tile that gets a QPixmap and i want to show it on a QGraphicsScene (screen), Its important that it will be able refresh when a new picture came in from the server side.
1) Does QGraphicsScene and QGraphicsView have to be declared in main?
no.

2) It is possible to use show() function in a non-QT class that have QT objects in it ?
The question is not clear.
You can call show() on objects that implement it.
3) It is possible at all???
What do you mean by "it"?