Code outlining is used within the code editor; it allows you to collapse or expand regions of code along these container boundaries. A series of grouping lines and expand/collapse boxes are drawn in the selection margin. These expand/collapse boxes are clickable, enabling you to hide or display lines of code based on the logical groupings.
Both Visual Basic and C# provide a way to manually create named regions of code via a special region keyword. Use
#End Region for Visual Basic) to create your own artificial code container that is appropriately parsed by the code outliner. Because each region is named, this is a handy approach for organizing and segregating the logical sections of your code. ...