You can append, insert, or remove loops from the boundaries of a Hatch object. Associative hatches are updated to match any changes made to their boundaries. Non-associative hatches are not updated.
To edit a hatch boundary, use one of the following methods:
Appends a loop to the hatch. You define the type of loop being appended with first parameter of the AppendLoop method and the constants defined by the HatchLoopTypes enum.
Gets the loop at a given index of a hatch.
Inserts a loop at a given index of a hatch.
Deletes a loop at a given index of a hatch.
To query a hatch boundary, use one of the following methods:
Gets the type of loop at a given index of a hatch.
Gets the number of loops of a hatch.
This example creates an associative hatch. It then creates a circle and appends the circle as an inner loop to the hatch.
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
<CommandMethod("EditHatchAppendLoop")> _
Public Sub EditHatchAppendLoop()
'' 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 an arc object for the closed boundary to hatch
Using acArc As Arc = New Arc(New Point3d(5, 3, 0), 3, 0, 3.141592)
acBlkTblRec.AppendEntity(acArc)
acTrans.AddNewlyCreatedDBObject(acArc, True)
'' Create an line object for the closed boundary to hatch
Using acLine As Line = New Line(acArc.StartPoint, acArc.EndPoint)
acBlkTblRec.AppendEntity(acLine)
acTrans.AddNewlyCreatedDBObject(acLine, True)
'' Adds the arc and line to an object id collection
Dim acObjIdColl As ObjectIdCollection = New ObjectIdCollection()
acObjIdColl.Add(acArc.ObjectId)
acObjIdColl.Add(acLine.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)
'' Create a circle object for the inner boundary of the hatch
Using acCirc As Circle = New Circle()
acCirc.Center = New Point3d(5, 4.5, 0)
acCirc.Radius = 1
acBlkTblRec.AppendEntity(acCirc)
acTrans.AddNewlyCreatedDBObject(acCirc, True)
'' Adds the circle to an object id collection
acObjIdColl.Clear()
acObjIdColl.Add(acCirc.ObjectId)
'' Append the circle as the inner loop of the hatch and evaluate it
acHatch.AppendLoop(HatchLoopTypes.Default, acObjIdColl)
acHatch.EvaluateHatch(True)
End Using
End Using
End Using
End Using
'' Save the new object to the database
acTrans.Commit()
End Using
End Sub
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
[CommandMethod("EditHatchAppendLoop")]
public static void EditHatchAppendLoop()
{
// 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 an arc object for the closed boundary to hatch
using (Arc acArc = new Arc(new Point3d(5, 3, 0), 3, 0, 3.141592))
{
acBlkTblRec.AppendEntity(acArc);
acTrans.AddNewlyCreatedDBObject(acArc, true);
// Create an line object for the closed boundary to hatch
using (Line acLine = new Line(acArc.StartPoint, acArc.EndPoint))
{
acBlkTblRec.AppendEntity(acLine);
acTrans.AddNewlyCreatedDBObject(acLine, true);
// Adds the arc and line to an object id collection
ObjectIdCollection acObjIdColl = new ObjectIdCollection();
acObjIdColl.Add(acArc.ObjectId);
acObjIdColl.Add(acLine.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);
// Create a circle object for the inner boundary of the hatch
using (Circle acCirc = new Circle())
{
acCirc.Center = new Point3d(5, 4.5, 0);
acCirc.Radius = 1;
acBlkTblRec.AppendEntity(acCirc);
acTrans.AddNewlyCreatedDBObject(acCirc, true);
// Adds the circle to an object id collection
acObjIdColl.Clear();
acObjIdColl.Add(acCirc.ObjectId);
// Append the circle as the inner loop of the hatch and evaluate it
acHatch.AppendLoop(HatchLoopTypes.Default, acObjIdColl);
acHatch.EvaluateHatch(true);
}
}
}
}
// Save the new object to the database
acTrans.Commit();
}
}
Sub EditHatchAppendLoop()
Dim hatchObj As AcadHatch
Dim patternName As String
Dim PatternType As Long
Dim bAssociativity As Boolean
' Define and create the hatch
patternName = "ANSI31"
PatternType = 0
bAssociativity = True
Set hatchObj = ThisDrawing.ModelSpace. _
AddHatch(PatternType, patternName, bAssociativity)
' Create the outer loop for the hatch.
Dim outerLoop(0 To 1) As AcadEntity
Dim center(0 To 2) As Double
Dim radius As Double
Dim startAngle As Double
Dim endAngle As Double
center(0) = 5: center(1) = 3: center(2) = 0
radius = 3
startAngle = 0
endAngle = 3.141592
Set outerLoop(0) = ThisDrawing.ModelSpace. _
AddArc(center, radius, startAngle, endAngle)
Set outerLoop(1) = ThisDrawing.ModelSpace. _
AddLine(outerLoop(0).startPoint, outerLoop(0).endPoint)
' Append the outer loop to the hatch object
hatchObj.AppendOuterLoop (outerLoop)
' Create a circle as the inner loop for the hatch.
Dim innerLoop(0) As AcadEntity
center(0) = 5: center(1) = 4.5: center(2) = 0
radius = 1
Set innerLoop(0) = ThisDrawing.ModelSpace. _
AddCircle(center, radius)
' Append the circle as an inner loop to the hatch
hatchObj.AppendInnerLoop (innerLoop)
' Evaluate and display the hatch
hatchObj.Evaluate
ThisDrawing.Regen True
End Sub