[SOLVED] Window vs Page vs Form

In terms of top level controls we have:

• Page. Which, as you wrote, covers the entire browser. There can be only one active page at a time. You can create as many pages as you like, but obviously only one can be visible. You can switch (navigate, in a way) by using Application.MainPage = page1. Or by calling Show() on the page, which will also change Application.MainPage. Switching pages gives a very nice navigation impression (we could add animations in the future).
• Form. Which is what I call Window sometimes. I wanted to call the class Window originally. A Form (or window) will always show in front of a Page.
• Desktop. The desktop control is similar to a  page. There can be only one active. You can show a desktop using Application.Desktop = desktop1. A desktop, when present, manages (minimize, thumbnails) all the forms. A desktop can be a child of a page but not of a form. A page can be designed in a way that it has desktop within, which can host the forms. When you switch a desktop, all the forms are automatically transferred to the new desktop.

The fourth control that can be designed is the UserControl. All it means is that it’s a design surface. Otherwise any control can have child controls.

We’ll add a fifth “designable” control as an extension: PopupControl. It will have a design surface, like the UserControl, and new properties to let you “hook” it to another control. So basically the PopupControl will allow you to add a ComboBox-like dropdown panel to anything.

HTH

Best,

Luca