C#.Net: Circle MText Objects Matching String Entered By User

In my last post we created a C#.Net program to place a red circle around all MText entities in a drawing. Let's add some code to allow the user to enter a specific string value to place circles around. The descriptive inline comments that were in the first program are not duplicated here for clarity.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Geometry;

namespace SLD_Demo

{

    public class MTextTools

    {

        [CommandMethod("SLDcirText")]

        public void SLDcirText()

        {

            //get current document

            Document acDoc =

                Application.DocumentManager.MdiActiveDocument;

            //get AutoCAD database

            Database acCurDb = acDoc.Database;

            //get string to search for

            String sldStrToSrch = SLDgetStringFromUser(acDoc);

            //start db transaction

            using (Transaction acTrans =

                acCurDb.TransactionManager.StartTransaction())

            {

                //open block table

                BlockTable bt = (BlockTable)acTrans.GetObject

                    (acCurDb.BlockTableId, OpenMode.ForRead);

                BlockTableRecord btr = (BlockTableRecord)

                    acTrans.GetObject(bt[BlockTableRecord.ModelSpace],

                    OpenMode.ForRead);

                //iterate through block table to locate mtext objects

                foreach (ObjectId id in btr)

                {

                    //open each object to read

                    DBObject obj = acTrans.GetObject

                        (id, OpenMode.ForRead);

                    //only deal with MText objects

                    MText dbMText = obj as MText;

                    //if current object is Mtext

                    if (dbMText != null)

                    {

                        //assign value of current MText object to a new

                        //String variable

                        String curTxtValue = dbMText.Contents;

                        //now compare to the string entered by user

                        /*I am using the Equals method and overriding to

                         not be case sensitive. This method is returning

                         a boolean value and we are looking for true.

                         There are several string comparison methods.

                         The Contains method would return true if the

                         string entered by user is a part of any Mtext

                         entities. The code for this is:

                           if (curTxtValue.Contains(sldStrToSrch))

                        */

                        if (string.Equals(sldStrToSrch, curTxtValue,

                            StringComparison.CurrentCultureIgnoreCase))

                        {

                            //draw a circle around the mtext entity

                            SLDdrawCir(acCurDb, acTrans, dbMText);

                        }

                    }

                }

                //commit the transaction so we do not leave the db open

                acTrans.Commit();

            }

        }

        //function to get text string from user

        public String SLDgetStringFromUser(Document acDoc)

        {

            PromptStringOptions pStrOpts = new PromptStringOptions(

                "\nFind What: ");

            //control the prompt string options to behave like we want

            //such as allow spaces to be entered

            pStrOpts.AllowSpaces = true;

            //retrieve the string entered by user

            PromptResult pStrRes = acDoc.Editor.GetString(pStrOpts);

            //and assign to a new string variable

            String sldStr = pStrRes.StringResult;

            //return the string variable to calling function

            return sldStr;

        }

        //function to draw circle around an MText object

        public void SLDdrawCir(Database acCurDb,

            Transaction acTrans, MText MtextObj)

        {

            //define a new point object for the center point of circle

            Point3d cenPoint = new Point3d();

            //use the location method of the Mtext object to define

            //the center point coordinates

            cenPoint = MtextObj.Location;

            //define a new Circle object

            /*we use the center point defined above, assign a diameter

             and assign a color using the ColorIndex method from the

             circle object*/

            Circle textCir = new Circle();

            textCir.Center = cenPoint;

            textCir.Diameter = 1.0;

            textCir.ColorIndex = 1;

            //now add the circle to the drawing (model space)

            /*We need to add it to the block table, this is the same

             basic operations when adding geometry to a drawing*/

            BlockTable acBlkTbl;

            acBlkTbl = acTrans.GetObject(

                acCurDb.BlockTableId, OpenMode.ForRead) as BlockTable;

            BlockTableRecord acBlkTblRec;

            acBlkTblRec = acTrans.GetObject(

                acBlkTbl[BlockTableRecord.ModelSpace],

                OpenMode.ForWrite)

                as BlockTableRecord;

            acBlkTblRec.AppendEntity(textCir);

            acTrans.AddNewlyCreatedDBObject(textCir, true);

        }

    }

}

To test this build the solution and NETLOAD the .dll into AutoCAD. Place some MText objects in the drawing and then type in SLDcirText at the command line. You will be prompted to enter a string to search for. Enter a string and regardless of case the matching strings should be circled.