hebackus AutoCAD 2026 .NET API Class Reference
Quick lookup for 1,248 classes across 28 namespaces
When to Use This Skill
- Looking for AutoCAD base classes
- Finding database entities (Line, Circle, Polyline, etc.)
- Checking geometry classes
- Finding editor/application classes
- Exploring runtime services
Common Patterns
Access Database and Transaction
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Runtime;
[CommandMethod("MYCOMMAND")]
public void MyCommand()
{
Document doc = Application.DocumentManager.MdiActiveDocument;
Database db = doc.Database;
Editor ed = doc.Editor;
using (Transaction tr = db.TransactionManager.StartTransaction())
{
// Work with database objects
BlockTable bt = tr.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;
BlockTableRecord btr = tr.GetObject(bt[BlockTableRecord.ModelSpace],
OpenMode.ForWrite) as BlockTableRecord;
tr.Commit();
}
}
Create Entity
using (Transaction tr = db.TransactionManager.StartTransaction())
{
BlockTable bt = tr.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;
BlockTableRecord btr = tr.GetObject(bt[BlockTableRecord.ModelSpace],
OpenMode.ForWrite) as BlockTableRecord;
// Create a line
Line line = new Line(new Point3d(0, 0, 0), new Point3d(100, 100, 0));
line.ColorIndex = 1; // Red
btr.AppendEntity(line);
tr.AddNewlyCreatedDBObject(line, true);
tr.Commit();
}
User Input
using Autodesk.AutoCAD.EditorInput;
Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
// Prompt for point
PromptPointOptions ppo = new PromptPointOptions("\nSelect point: ");
PromptPointResult ppr = ed.GetPoint(ppo);
if (ppr.Status == PromptStatus.OK)
{
Point3d pt = ppr.Value;
}
// Prompt for entity
PromptEntityOptions peo = new PromptEntityOptions("\nSelect entity: ");
peo.SetRejectMessage("\nMust be a line.");
peo.AddAllowedClass(typeof(Line), true);
PromptEntityResult per = ed.GetEntity(peo);
if (per.Status == PromptStatus.OK)
{
ObjectId lineId = per.ObjectId;
}
Full Class Index
See ../../autocad-api-reference/CLASS_INDEX.md for complete listing of all 1,248 types.
Related Skills
For Civil 3D-specific classes, use:
/c3d-api:c3d-class-reference- Civil 3D classes/c3d-api:c3d-root-objects- CivilApplication/CivilDocument
For specific AutoCAD entity and API topics, use:
/c3d-api:acad-tables- Creating and modifying AutoCAD table entities/c3d-api:acad-geometry- Working with geometric types (Point3d, Vector3d, curves)/c3d-api:acad-mtext- Creating and formatting MText entities/c3d-api:acad-mleaders- Creating and configuring MLeader entities/c3d-api:acad-fields- Working with AutoCAD field expressions/c3d-api:acad-dimensions- Creating dimension entities/c3d-api:acad-hatches- Creating hatch pattern fills/c3d-api:acad-blocks- Creating and inserting block references/c3d-api:acad-sheet-sets- Reading/writing Sheet Set (.dst) files via COM/c3d-api:acad-layers- Layer table, layer records, properties, and states/c3d-api:acad-editor-input- Editor prompts, selection sets, and filters/c3d-api:acad-polylines- Polyline, Polyline2d, Polyline3d entity details
Documentation
- HTML Docs:
ac3d_netapi2docs/docs/AutoCAD_2026/html/index.html - Source Code:
ac3d_netapi2docs/src/AutoCAD_2026/