Gets the collection of group specifiers using the TimeUnits enumeration. The index of each specifier indicates (level-1). Specifiers modified using the collection Add, Insert and Remove methods of the collection. If no values are specified, values are automatically selected based on the range.

'宣言
 
Public ReadOnly Property GroupTypes As System.Collections.ObjectModel.ObservableCollection(Of TimeUnits)

public System.Collections.ObjectModel.ObservableCollection<TimeUnits> GroupTypes {get;}