Architectural Design Principles of WPF

The design principles behind Windows Presentation Foundation can be categorized as follows:

Integration: Windows Presentation Foundation offers a unified API that spans the services identified in Table 1. Developers today are faced with a myriad choice of disparate technologies and APIs, depending on whether they are targeting 2D graphics (GDI or GDI+), user interface (USER32 or Windows Forms), media (DirectShow), or 3D (Direct3D or OpenGL). Windows Presentation Foundation provides a single model that is orthogonal across all these services and allows seamless integration of content within a single application. You can use the same constructs for animation, data binding and styling, regardless of whether you are targeting 2D, 3D or text content.

Vector graphics: As described in the introduction, Windows Presentation Foundation takes full advantage of the powerful Graphical Processing Units that are part of modern PC systems. At its heart, the composition engine is vector-based, allowing for scaling of all output to match the resolution of a specific machine. The rendering architecture uses Direct3D for all output: on video cards that implement DirectX 7 or later in hardware, Windows Presentation Foundation renders output using the GPU wherever possible. In situations where hardware rendering cannot be used, software rendering is available as a fallback. Lastly, a floating-point logical pixel system and 32-bit ARGB color support provide a rich high-fidelity experience that anticipates future technology needs, such as high-DPI displays.

Declarative programming: Windows Presentation Foundation introduces XAML (eXtensible Application Markup Language), an XML-based language for instantiating and populating nested object hierarchies. While XAML isn't exclusively tied to Windows Presentation Foundation, it is inherently suitable for tasks such as UI definition and construction. The design of XAML allows applications to parse and manipulate UI logic at run-time for dynamic workflow scenarios. Importantly, the XAML / code-behind model embodied in Windows Presentation Foundation allows designers and developers to work collaboratively on client application design and development, using tools such as Expression as well as third-party specialist tools including ZAM 3D and Mobiform Aurora.

Easy deployment: With support for both standalone applications and Web-browser applications, Windows Presentation Foundation offers the best of both deployment models. Web-browser applications run from within Internet Explorer, either occupying the entire window or within an inline frame. They offer the ease of deployment for which Web applications are famed, as well as operating within a partial trust sandbox that protects the client machine against malicious applications. Yet they can still take advantage of the local client hardware and use 3D and media services for the richest Web experience available today. On the other hand, standalone applications are locally installed via ClickOnce or MSI technologies and offer full access to the underlying platform.

Document lifecycle: Windows Presentation Foundation introduces a new set of document and print technologies. Applications that need to persist data to a local store can use the Open Packaging Conventions, a ZIP-based packaging convention shared with Office 2007 that supports core properties and custom metadata, digital signatures and rights management functionality. For applications that want to share documents for collaboration across multiple machines, even without the application installed, the XML Paper Specification allows visuals to be fixed in a printable, portable format.