Gets or sets this NavigationPane's current state.
A DevExpress.XtraBars.Navigation.NavigationPaneState enumerator value that is this NavigationPane's current state.
Depending on the State property value, the NavigationPane can be in three unique states:
- Regular - the content area is visible and occupies the size specified by the NavigationPane.RegularSize property;
- Expanded - the content area is visible and occupies all available space, specified by the MaximumSize property;
- Collapsed - the content area is collapsed, only the column with page headers is visible;
- Default - equal to the Regular state.