Programming WPF, 2nd Edition

Silverlight XAML

Even though the XAML defined for use in Silverlight is not tied to WPF XAML, the Silverlight team has made an effort to use WPF XAML as a starting place for its XAML design. In this first release of Silverlight, all the XAML tags used in Silverlight are also compatible with WPF.

Tip

Compatibility will be a priority in future releases. However, because WPF and Silverlight are evolving in parallel, you can expect that some innovations in the markup introduced on one platform may or may not appear on the other.

For the WPF developer, the most glaring omission is that it does not offer any built-in controls. Silverlight aims to provide the maximum functionality for the smallest download cost. Because of this design goal, no WPF controls are supported initially. This means no text boxes, no buttons, no combo boxes, and, in fact, nothing from WPF that derives from the Control base class at all.

As developers (and designers), it may seem that the exclusion of controls from the XAML is a show-stopper. Silverlight's goals are to have a small runtime and to be cross-platform-compatible. In this first release, Silverlight is attempting to fulfill some very specific web-related use cases:

• Video (e.g., sites like YouTube.com and Soapbox.msn.com)

• Animation (e.g., sites like Jibjab.com and Funnyflash.com)

• User interaction (e.g., sites like Gamespot.com)

These use cases mean that in addition to no control support, there is no 3D support or templates, and there is limited resource use, ...