In yesterday’s demo, I gave instructions to add references to WindowsBase, PresentationCore, and PresentationFoundation. Today I thought we’d take a few minutes to talk about what these are and what they do.
Together these three DLLs make up the heart of Windows Presentation Foundation. WindowsBase defines most of the base types needed by WPF, and should always be included. PresentationCore builds on WindowsBase by providing the base types for most of the GUI components you’ll use. PresentationFoundation is the big animal on the block, he holds all of the WPF controls.
Now that you know the DLLs, let’s talk briefly about the namespaces you’ll encounter. System.Windows contains two core types, Application and Window. These are the two you’ll use as a platform to build your user interfaces on, and you’ll see them often.
The other one you saw yesterday was System.Windows.Controls. In here are all of the standard controls you might expect: button, label, textbox, checkbox, etc. Yesterday when you saw the XAML <Label> block, WPF renders that from the System.Windows.Controls namespace. By the way, you need to note that XAML, like C#, is case sensitive. So <Label> will work, but <label> and <LABEL> will not.
Over time there are some other children of System.Windows we’ll be seeing, such as Shapes (which, as you might guess holds standard shapes like rectangles and circles), Media (used for 3D and more), Document (for creating XPS files), and Markup which can be used to parse XAML.
We’ll dive deeper into all of these as time goes by, but I wanted to give you a brief introduction so you’d understand what bits belonged where in the WPF world, and why you need to include those references and using/import statements in your code.
Arcane Code 