"Pro WPF with VB 2008: Windows Presentation Foundation with .NET 3.5"
Nested content doesn??™t always indicate a collection. For example, consider the Grid element, which contains several other controls: ... ...
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These nested tags don??™t correspond to complex properties because they don??™t include the period. Furthermore, the Grid control isn??™t a collection and so it doesn??™t implement IList or IDictionary. What the Grid does support is the ContentProperty attribute, which indicates the property that should receive any nested content. Technically, the ContentProperty attribute is applied to the Panel class, from which the Grid derives, and looks like this: _ Public MustInherit Class Panel This indicates that any nested elements should be used to set the Children property. The XAML parser treats the content property differently depending on whether or not it??™s a collection property (in which case it implements the IList or IDictionary interface). Because the CHAPTER 2 n XAML 40 Panel.Children property returns a UIElementCollection, and because UIElementCollection implements IList, the parser uses the IList.Add() method to add nested content to the grid.