You can change the angle or spacing of an existing hatch pattern or replace it with a solid-fill, gradient fill, or one of the predefined patterns that AutoCAD offers. The Pattern option in the Boundary Hatch dialog box displays a list of these patterns. To reduce file size, the hatch is defined in the drawing as a single graphic object.
Use the following properties and methods to edit the hatch patterns:
Change the pattern spacing of a hatch
This example creates a hatch. It then adds two to the current pattern spacing for the hatch.
VB.NET
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
<CommandMethod("EditHatchPatternScale")> _
Public Sub EditHatchPatternScale()
'' Get the current document and database
Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument
Dim acCurDb As Database = acDoc.Database
'' Start a transaction
Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()
'' Open the Block table for read
Dim acBlkTbl As BlockTable
acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, _
OpenMode.ForRead)
'' Open the Block table record Model space for write
Dim acBlkTblRec As BlockTableRecord
acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _
OpenMode.ForWrite)
'' Create a circle object for the boundary of the hatch
Using acCirc As Circle = New Circle()
acCirc.Center = New Point3d(5, 3, 0)
acCirc.Radius = 3
acBlkTblRec.AppendEntity(acCirc)
acTrans.AddNewlyCreatedDBObject(acCirc, True)
'' Adds the arc and line to an object id collection
Dim acObjIdColl As ObjectIdCollection = New ObjectIdCollection()
acObjIdColl.Add(acCirc.ObjectId)
'' Create the hatch object and append it to the block table record
Using acHatch As Hatch = New Hatch()
acBlkTblRec.AppendEntity(acHatch)
acTrans.AddNewlyCreatedDBObject(acHatch, True)
'' Set the properties of the hatch object
'' Associative must be set after the hatch object is appended to the
'' block table record and before AppendLoop
acHatch.SetHatchPattern(HatchPatternType.PreDefined, "ANSI31")
acHatch.Associative = True
acHatch.AppendLoop(HatchLoopTypes.Outermost, acObjIdColl)
'' Evaluate the hatch
acHatch.EvaluateHatch(True)
'' Increase the pattern scale by 2 and re-evaluate the hatch
acHatch.PatternScale = acHatch.PatternScale + 2
acHatch.SetHatchPattern(acHatch.PatternType, acHatch.PatternName)
acHatch.EvaluateHatch(True)
End Using
End Using
'' Save the new object to the database
acTrans.Commit()
End Using
End Sub
C#
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
[CommandMethod("EditHatchPatternScale")]
public static void EditHatchPatternScale()
{
// Get the current document and database
Document acDoc = Application.DocumentManager.MdiActiveDocument;
Database acCurDb = acDoc.Database;
// Start a transaction
using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
{
// Open the Block table for read
BlockTable acBlkTbl;
acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,
OpenMode.ForRead) as BlockTable;
// Open the Block table record Model space for write
BlockTableRecord acBlkTblRec;
acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],
OpenMode.ForWrite) as BlockTableRecord;
// Create a circle object for the boundary of the hatch
using (Circle acCirc = new Circle())
{
acCirc.Center = new Point3d(5, 3, 0);
acCirc.Radius = 3;
acBlkTblRec.AppendEntity(acCirc);
acTrans.AddNewlyCreatedDBObject(acCirc, true);
// Adds the arc and line to an object id collection
ObjectIdCollection acObjIdColl = new ObjectIdCollection();
acObjIdColl.Add(acCirc.ObjectId);
// Create the hatch object and append it to the block table record
using (Hatch acHatch = new Hatch())
{
acBlkTblRec.AppendEntity(acHatch);
acTrans.AddNewlyCreatedDBObject(acHatch, true);
// Set the properties of the hatch object
// Associative must be set after the hatch object is appended to the
// block table record and before AppendLoop
acHatch.SetHatchPattern(HatchPatternType.PreDefined, "ANSI31");
acHatch.Associative = true;
acHatch.AppendLoop(HatchLoopTypes.Outermost, acObjIdColl);
// Evaluate the hatch
acHatch.EvaluateHatch(true);
// Increase the pattern scale by 2 and re-evaluate the hatch
acHatch.PatternScale = acHatch.PatternScale + 2;
acHatch.SetHatchPattern(acHatch.PatternType, acHatch.PatternName);
acHatch.EvaluateHatch(true);
}
}
// Save the new object to the database
acTrans.Commit();
}
}
