Site.md

Site Class

Overview

Site is a fundamental topological container in Civil 3D. It acts as a bucket for related objects that interact with each other, specifically Parcels, Alignments, and Gradings. Objects within the same Site automatically interact (e.g., alignments subdivide parcels).

Namespace

Autodesk.Civil.DatabaseServices

Inheritance Hierarchy

System.Object
  └─ RXObject
      └─ DBObject
          └─ Entity
              └─ Feature
                  └─ Site

Key Properties

Property	Type	Description
Name	string	Name of the site.
Parcels	ObjectId	ID of the parcel collection.
Alignments	ObjectId	ID of the alignment collection.
FeatureLines	ObjectId	ID of the feature line collection.

Key Methods

Method	Return Type	Description
Create(CivilDocument, string)	ObjectId	Static method to create a new site.

Code Examples

Example 1: Creating a New Site

using (Transaction tr = db.TransactionManager.StartTransaction())
{
    CivilDocument civDoc = CivilApplication.ActiveDocument;
    
    ObjectId siteId = Site.Create(civDoc, "Phase 1 Development");
    
    // Site is now ready to accept parcels/alignments
    tr.Commit();
}

Example 2: Iterating Existing Sites

CivilDocument civDoc = CivilApplication.ActiveDocument;

foreach (ObjectId siteId in civDoc.GetSiteIds())
{
    using (Transaction tr = db.TransactionManager.StartTransaction())
    {
        Site site = tr.GetObject(siteId, OpenMode.ForRead) as Site;
        ed.WriteMessage($"\nSite: {site.Name}");
    }
}

Example 3: Finding a Site mainly by Name

public ObjectId FindSite(string name)
{
    CivilDocument civDoc = CivilApplication.ActiveDocument;
    foreach (ObjectId id in civDoc.GetSiteIds())
    {
        Site s = id.GetObject(OpenMode.ForRead) as Site;
        if (s.Name.Equals(name, StringComparison.OrdinalIgnoreCase))
            return id;
    }
    return ObjectId.Null;
}

Example 4: Getting Parcel Collection

// The Site object DOES NOT directly expose a "Parcels" collection property
// Instead, you usually access parcels via the CivilDocument or by checking the Site's dependency collections (which is handled internally).
// Wait - API correction:
// In .NET, Site properties like .Parcels don't exist directly as lists.
// You usually create adjacent objects *referencing* the site.
// OR use container properties if available in specific version.
// Correct approach: Access collections via the site ID.

Example 5: Moving Objects to Site

// You don't "move" objects; you create them in the site.
// Changing a Parcel's site usually involves recreation or specific MoveToSite APIs if available.

Example 6: Deleting a Site

// Standard DBObject usage
site.Erase(); // Removes site AND its topological content

Example 7: Renaming

site.Name = "New Site Name";

Example 8: Topology Logic

// Objects in this site:
// 1. Alignments cut through Parcels
// 2. Grading Groups interact
// 3. Objects in DIFFERENT sites do not interact.

Best Practices

1. Separation: Use different Sites to prevent unwanted interaction. For example, keep "Existing Conditions" alignments separate from "Proposed" parcels if you don't want them to subdivide.
2. "None" Site: Some objects can be "siteless" (Site ObjectId.Null). This prevents all topological interaction.

Related Objects

• Parcel
• Alignment

References

• Autodesk Site Reference