WPF GroupBox Header StringFormat Binding
When you try to use StringFormat binding for a GroupBox Header in WPF, you might find it does not work! Some people mentioned there is a HeaderStringFormat but not StringFormat, but at least in .NET 4.5, we can not find out a HeaderStringFormat.
WPF Data Binding Using Code Behind and XAML
You can use either of code behind or XAML to implement data binding in WPF:
WPF DependencyProperties vs INotifyPropertyChanged
There are 2 ways to get the automatic notice target object if the source object changed (for example: the value) when you using WPF data binding: the one is Dependency Properties, the other one is INotifyPropertyChanged: