Create Linear Dimensions

Linear dimensions can be aligned or rotated. Aligned dimensions have the dimension line parallel to the line along which the extension line origins lie. Rotated dimensions have the dimension line placed at an angle to the extension line origins.

You create linear dimensions by creating instances of the AlignedDimension and RotatedDimension objects. After you create an instance of a linear dimensions, you can modify the text, the angle of the text, or the angle of the dimension line. The following illustrations show how the type of linear dimension and the placement of the extension line origins affect the angle of the dimension line and text.

When you create an instance of an AlignedDimension object, you have the option to specify the extension line origins, the location of the dimension line, dimension text, and the dimension style to apply. If you do not pass any parameters into the AlignedDimension object constructor, the object is assigned a set of default property values.

The RotatedDimension object constructor offers the same options as the AlignedDimension object constructor, with one exception. The RotatedDimension object constructor takes an additional paramter that specifies the angle at which the dimension line is rotated.

For additional information about creating linear dimensions, see “Create Linear Dimensions” in the AutoCAD User's Guide.

Dimension joglines

Joglines on linear dimensions are not added through a set of properties, but extended data(Xdata). The application name responsible for dimension joglines is ACAD_DSTYLE_DIMJAG_POSITION. The following is an example of the Xdata structure that needs to be appended to a linear dimension.

VB.NET

'' Open the Registered Application table for read

Dim acRegAppTbl As RegAppTable

acRegAppTbl = <transaction>.GetObject(<current_database>.RegAppTableId, _

                                      OpenMode.ForRead)

'' Check to see if the app "ACAD_DSTYLE_DIMJAG_POSITION" is

'' registered and if not add it to the RegApp table

If acRegAppTbl.Has("ACAD_DSTYLE_DIMJAG_POSITION") = False Then

    Dim acRegAppTblRec As RegAppTableRecord = New RegAppTableRecord()

    acRegAppTblRec.Name = "ACAD_DSTYLE_DIMJAG_POSITION"

    acRegAppTbl.UpgradeOpen()

    acRegAppTbl.Add(acRegAppTblRec)

    <transaction>.AddNewlyCreatedDBObject(acRegAppTblRec, True)

End If

'' Create a result buffer to define the Xdata

Dim acResBuf As ResultBuffer = New ResultBuffer()

acResBuf.Add(New TypedValue(DxfCode.ExtendedDataRegAppName, _

                                    "ACAD_DSTYLE_DIMJAG_POSITION"))

acResBuf.Add(New TypedValue(DxfCode.ExtendedDataInteger16, 387))

acResBuf.Add(New TypedValue(DxfCode.ExtendedDataInteger16, 3))

acResBuf.Add(New TypedValue(DxfCode.ExtendedDataInteger16, 389))

acResBuf.Add(New TypedValue(DxfCode.ExtendedDataXCoordinate, _

                                    New Point3d(-1.26985, 3.91514, 0)))

'' Attach the Xdata to the dimension

<dimension_object>.XData = acResBuf

// Open the Registered Application table for read

RegAppTable acRegAppTbl;

acRegAppTbl = <transaction>.GetObject(<current_database>.RegAppTableId,

                                      OpenMode.ForRead) as RegAppTable;

// Check to see if the app "ACAD_DSTYLE_DIMJAG_POSITION" is

// registered and if not add it to the RegApp table

if (acRegAppTbl.Has("ACAD_DSTYLE_DIMJAG_POSITION") == false)

    RegAppTableRecord acRegAppTblRec = new RegAppTableRecord();

    acRegAppTblRec.Name = "ACAD_DSTYLE_DIMJAG_POSITION";

    acRegAppTbl.UpgradeOpen();

    acRegAppTbl.Add(acRegAppTblRec);

    <transaction>.AddNewlyCreatedDBObject(acRegAppTblRec, true);

// Create a result buffer to define the Xdata

ResultBuffer acResBuf = new ResultBuffer();

acResBuf.Add(new TypedValue((int)DxfCode.ExtendedDataRegAppName,

                                         "ACAD_DSTYLE_DIMJAG_POSITION"));

acResBuf.Add(new TypedValue((int)DxfCode.ExtendedDataInteger16, 387));

acResBuf.Add(new TypedValue((int)DxfCode.ExtendedDataInteger16, 3));

acResBuf.Add(new TypedValue((int)DxfCode.ExtendedDataInteger16, 389));

acResBuf.Add(new TypedValue((int)DxfCode.ExtendedDataXCoordinate,

                                         new Point3d(-1.26985, 3.91514, 0)));

// Attach the Xdata to the dimension

<dimension_object>.XData = acResBuf;

VBA/ActiveX Code Reference

Create a rotated linear dimension

This example creates a rotated dimension in Model space.

VB.NET

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

<CommandMethod("CreateRotatedDimension")> _

Public Sub CreateRotatedDimension()

  '' Get the current 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 the rotated dimension

      Dim acRotDim As RotatedDimension = New RotatedDimension()

      acRotDim.XLine1Point = New Point3d(0, 0, 0)

      acRotDim.XLine2Point = New Point3d(6, 3, 0)

      acRotDim.Rotation = 0.707

      acRotDim.DimLinePoint = New Point3d(0, 5, 0)

      acRotDim.DimensionStyle = acCurDb.Dimstyle

      '' Add the new object to Model space and the transaction

      acBlkTblRec.AppendEntity(acRotDim)

      acTrans.AddNewlyCreatedDBObject(acRotDim, True)

      '' Commit the changes and dispose of the transaction

      acTrans.Commit()

  End Using

End Sub

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.Geometry;

[CommandMethod("CreateRotatedDimension")]

public static void CreateRotatedDimension()

  // Get the current 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 the rotated dimension

      RotatedDimension acRotDim = new RotatedDimension();

      acRotDim.XLine1Point = new Point3d(0, 0, 0);

      acRotDim.XLine2Point = new Point3d(6, 3, 0);

      acRotDim.Rotation = 0.707;

      acRotDim.DimLinePoint = new Point3d(0, 5, 0);

      acRotDim.DimensionStyle = acCurDb.Dimstyle;

      // Add the new object to Model space and the transaction

      acBlkTblRec.AppendEntity(acRotDim);

      acTrans.AddNewlyCreatedDBObject(acRotDim, true);

      // Commit the changes and dispose of the transaction

      acTrans.Commit();

VBA/ActiveX Code Reference