Gets the number of items contained in a collection.
Each collection type potentially implements this differently. The most common equivalent for Silverlight programming is PresentationFrameworkCollection<T>.Count.
For several common Silverlight elements, you can get the relevant collection and enumerate the child items of a parent object by accessing the Children collection of the parent object (Canvas.Children, GeometryGroup.Children, Storyboard.Children, TransformGroup.Children). Other commonly used collection properties are Path.Data, TextBlock.Inlines, and LinearGradientBrush.GradientStops.
Using the Count property with an object that does not support a collection will raise a Silverlight run-time error.