WPF DataGrid 的 Items 和 ItemsSource 属性之间有什么区别？

Question

From what I can gather from Intellisense, the difference is the return types and the ItemsSource has a setter whereas Items simply has a getter. Practically speaking though, I do not understand the need for these two properties being separate from each other instead of just being one property.

Could someone explain to me why these are separate properties instead of just one property?

And also, if I'm missing something, could someone please explain to me when I'd want to use one over the other (besides the obvious need of a setter)? Eg, when specifically would I want to use Items over ItemsSource?

Answer 1

What's the difference between a WPF DataGrid's Items and ItemsSource properties?

A DataGrid is an ItemsControl so this applies to all other ItemsControl classes as well.

• The Items property is an ItemCollection and is filled in through XAML. It holds objects but is intended for FrameworkElements.

• The ItemsSource is bindable to a simple IEnumerable, with the ability to support INotifyCollectionChanged when available. It also supports DataTemplates.

when specifically would I want to use Items over ItemsSource?

ItemsSource is for databinding to a ViewModel.

You would use Items only in a few situations where you have a fixed number of XAML items. Unlikely for a Grid, more usable for a ComboBox.

You never use both at the same time.

This MSDN Page shows the typical usage for both.