Adding Mleader style

By Virupaksha Aithal

Mleader styles are stored under a NOD named “ACAD_MLEADERSTYLE”. You can directly get the object id of this dictionary using database property “MLeaderStyleDictionaryId”. Below code shows the procedure to add a new mleader style to database. The code also makes it current by setting the database property “MLeaderstyle”.

[CommandMethod("AddMleaderStyle")]
static public void AddMleaderStyle()
{
 
    Document doc = Application.DocumentManager.MdiActiveDocument;
    Database db = doc.Database;
    Editor ed = doc.Editor;
 
    using (Transaction tr =
                       db.TransactionManager.StartTransaction())
    {
        //Name of the mleader Style to edit
        const string styleName = "Test";
 
        DBDictionary mlstyles = (DBDictionary)tr.GetObject(
                                        db.MLeaderStyleDictionaryId,
                                        OpenMode.ForRead);
 
        ObjectId mLeaderStyle = ObjectId.Null;
 
        if (!mlstyles.Contains(styleName))
        {
           //add a new mleader style...
            MLeaderStyle newStyle = new MLeaderStyle();
 
            //make the arrow head as DOT.
            BlockTable blockTable = tr.GetObject(db.BlockTableId,
                                OpenMode.ForRead) as BlockTable;
            if (!blockTable.Has("_DOT"))
            {
                //load
                Application.SetSystemVariable("DIMBLK", "_DOT");
            }
            //now set the arrow hear.
            newStyle.ArrowSymbolId = blockTable["_DOT"];
 
            mLeaderStyle = 
                newStyle.PostMLeaderStyleToDb(db, styleName);
            tr.AddNewlyCreatedDBObject(newStyle, true);
        }
        else
        {
            mLeaderStyle = mlstyles.GetAt(styleName);
        }
 
        //make the new leader as current...
        db.MLeaderstyle = mLeaderStyle;
        tr.Commit();
    }
}