WPF Architecture

The Major components of WPF Architecture are Presentation Framework, Presentation Core and Media Integration Layer. The architecture divides in three major groups Managed Layer, Media Integration Layer (Unmanaged code) and Core Operating System.

Managed layer contains WindowsBase, Presentation Framework and Presentation Core assembly. Media Integration Layer contains Milcore(Media Integration Library Core)  and WindowsCodecs modules and both are unmanaged code. Media Integration Layer interacts with Direct3D and Direct3D interacts with Device Driver.

Managed Layer

Presentation Framework – Holds top level WPF types includes Window, Controls, Styles, and Layout Panels etc. The code and controls written in WPF Application is mostly interacting with this layer.

Presentation Core – Holds base types such as UI Element and Visual. Almost all the controls you are directly interacting with are derived from these types. Presentation Framework uses most of the types defined in this layer.

WindowBase: They hold even more basic elements which are capable of being used outside the WPF environment like Dispatcher.

Unmanaged Layer(milcore.dll) 

MilCore – Media Integration Library is core rendering system. MIL is unmanaged code. This layer converts WPF elements into the format that Direct3D expects. Windows7 & Windows Vista use this assembly to render its Desktop.

WindowsCodecs– This is low level API which gives imaging support in WPF applications. Provides supports for imaging like image processing, image displaying and scaling etc.

Direct3D – This layer is used to render graphics created using WPF Applications.

User32:- This provides the windows look and feel for buttons and textboxes and other UI elements. User32 lacked drawing capabilities.

GDI (Graphics device interface):- Microsoft introduced GDI to provide drawing capabilities. GDI not only provided drawing capabilities but also provided a high level of abstraction on the hardware display. In other words it encapsulates all complexities of hardware in the GDI API.

GDI+:- GDI+ was introduced which basically extends GDI and provides extra functionalities like jpg and PNG support, gradient shading and anti-aliasing. The biggest issue with GDI API was it did not use hardware acceleration and did not have animation and 3D support.