Application: SpanDirection
Revit Platform: Structure
Revit Version: 2011.0
First Released For: 8.1
Programming Language: C#
Skill Level: Beginning
Category: Parameters, Elements
Type: ExternalCommand

Subject: Date retrieval for structural Floor (Slab).
Summary: 
This sample demonstrates how to get span direction and span direction symbols of structural Floor (Slab).

Classes: 
Autodesk.Revit.UI.IExternalCommand
Autodesk.Revit.DB.ElementSet
Autodesk.Revit.DB.Floor
Autodesk.Revit.DB.ElementArray
Autodesk.Revit.DB.ElementArrayIterator

Project Files: 
Command.cs
This file contains the class Command which inherits from IExternalCommand interface and implements the Execute method, the class implements all functionalities of getting relevant information of Floor.

Description: 
This sample uses Floor class mostly to implement the functionality of getting properties of Floor (Slab): span direction angle and span direction symbols.
-	Floor objects can be gotten from ActiveDocument.Selection.Elements.
-	Floor.SpanDirectionAngle and Floor.SpanDirectionSymbols properties can be used to retrieve the span direction angle and span direction symbols of Floor (Slab).
-	To get span direction symbols, Element.ObjectType.Name 

Instructions: 
1.	Start Revit Structure, draw one slab in Reivt, and then select it.
2.	Click the external command, a message box will pop up, the span direction angle and span direction symbols of this slab will be shown afterwards. 
3.	If you fail to create a slab with span direction, please use “Structural Analysis-Default.rte” file as Revit Structure default template file.
4.	One .rvt file named SpanDirection.rvt is available under sample project folder, span direction and symbol of span direction have been added, you can open this file and select the existing floor to run the sample.