"Pro WPF with VB 2008: Windows Presentation Foundation with .NET 3.5"
This list of properties is just as notable for what it doesn??™t contain. If you??™re looking for familiar position properties, such as Top, Right, and Location, you won??™t find them. That??™s because most layout containers (all except for the Canvas) use automatic layout and don??™t give you the ability to explicitly position elements. Alignment To understand how these properties work, take another look at the simple StackPanel shown in Figure 4-2. In this example??”a StackPanel with vertical orientation??”the VerticalAlignment property has no effect because each element is given as much height as it needs and no more. However, the HorizontalAlignment is important. It determines where each element is placed in its row. Ordinarily, the default HorizontalAlignment is Left for a label and Stretch for a Button. That??™s why every button takes the full column width. However, you can change these details:
Figure 4-4 shows the result. The first two buttons are given their minimum sizes and aligned accordingly, while the bottom two buttons are stretched over the entire StackPanel.