Insert Hatch by Entities or Internal Points Example (C#)

//--------------------------------------------------------------
// Preconditions:
// 1. Create a C# Windows console project.
// 2. Copy and paste this example into the C# IDE.
// 3. Add a reference to:
//    install_dir\APISDK\tlb\DraftSight.Interop.dsAutomation.dll.
// 4. Add references to System and System.Windows.Forms.
// 5. Start DraftSight and open a drawing document with sketch entities.
// 6. Start debugging the project.
//
// In the DraftSight command window, choose how the Hatch should be inserted:
//    1. Type Entities.
//    2. Select the sketch entities that form the boundary of the area to be hatched.
//    3. Press Enter when finished.
//    - or -
//    1. Type InternalPoints.
//    2. Select three points that are in enclosed areas of the drawing.
//
// Postconditions: A Hatch is inserted, and the drawing document
// is zoomed to fit.
//----------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Text;
using DraftSight;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Diagnostics;

namespace AddHatch
{
    class Program
    {
        private static DraftSight.Application dsApp;
        private static DraftSight.Document dsDoc;

        static void Main(string[] args)
        {
            //Connect to DraftSight application
            dsApp = ConnectToDraftSight();
            if (null == dsApp)
            {
                return;
            }

            dsApp.AbortRunningCommand(); // abort any command currently running in DraftSight to avoid nested commands

            //Get active document
            dsDoc = dsApp.GetActiveDocument();
            if (null == dsDoc)
            {
                MessageBox.Show("There are no open documents in DraftSight.");
                return;
            }

            //Get model space
            Model dsModel = dsDoc.GetModel();

            //Get sketch manager
            SketchManager dsSketchMgr = dsModel.GetSketchManager();

            //Get command message object
            CommandMessage dsCommandMessage = dsApp.GetCommandMessage();

            //Display a prompt at the command line to create Hatch by entities or by internal points
            string[] keywords = { "Entities", "InternalPoints" };
            string selectedKeyword;
            bool promptResult = dsCommandMessage.PromptForKeyword("Insert Hatch by:", keywords, keywords[0], out selectedKeyword);
            if (promptResult)
            {
                //The user selected "By Entities" option
                if (selectedKeyword.ToUpper() == "_" + keywords[0].ToUpper() ||
                    selectedKeyword.ToUpper() == keywords[0].ToUpper())
                {
                    DispatchWrapper[] selectedEntities = SelectEntities(dsCommandMessage);

                    InsertHatchByEntities(dsSketchMgr, selectedEntities);
                }

                //The user selected "By Internal Points" option
                if (selectedKeyword.ToUpper() == "_" + keywords[1].ToUpper())
                {
                    //Select three internal points
                    int pointsCount = 3;

                    dsCommandMessage.PrintLine("Select three internal points for a hatch");

                    double[] internalPoints = SelectPoints(dsCommandMessage, pointsCount);

                    InsertHatchByInternalPoints(dsSketchMgr, internalPoints);
                }
            }
        }

        private static void InsertHatchByInternalPoints(SketchManager dsSketchMgr, double[] internalPoints)
        {
            //Hatch parameters
            string patternName = "ANSI31";
            double patternScale = 1;
            double patternAngle = 0;

            //Insert Hatch
            Hatch dsHatch = dsSketchMgr.InsertHatchByInternalPoints(internalPoints, patternName, patternScale, patternAngle);
            if (null != dsHatch)
            {
                //Change color of Hatch
                Color dsColor = dsHatch.Color;
                dsColor.SetNamedColor(dsNamedColor_e.dsNamedColor_Green);
                dsHatch.Color = dsColor;

                //Zoom to fit
                dsApp.Zoom(dsZoomRange_e.dsZoomRange_Fit, null, null);
            }
            else
            {
                MessageBox.Show("Hatch entity was not added to the current drawing.");
            }
        }

        private static double[] SelectPoints(CommandMessage dsCommandMessage, int internalPointsCount)
        {
            List<double> internalPoints = new List<double>();

            //Display prompt for point
            double x, y, z;
            int count = 0;
            while (count < internalPointsCount)
            {
                if (dsCommandMessage.PromptForPoint("Specify internal point", out x, out y, out z))
                {
                    internalPoints.Add(x);
                    internalPoints.Add(y);
                }

                count++;
            }

            return internalPoints.ToArray();
        }

        private static void InsertHatchByEntities(SketchManager dsSketchMgr, DispatchWrapper[] dsEntities)
        {
            //Hatch parameters
            string patternName = "GRASS";
            double patternScale = 1;
            double patternAngle = 0;

            //Insert Hatch
            Hatch dsHatch = dsSketchMgr.InsertHatchByEntities(dsEntities, patternName, patternScale, patternAngle);
            if (null != dsHatch)
            {
                //Change color of Hatch
                Color dsColor = dsHatch.Color;
                dsColor.SetNamedColor(dsNamedColor_e.dsNamedColor_Blue);
                dsHatch.Color = dsColor;

                //Zoom to fit
                dsApp.Zoom(dsZoomRange_e.dsZoomRange_Fit, null, null);
            }
            else
            {
                MessageBox.Show("Hatch entity was not added to the current drawing.");
            }
        }

        private static DispatchWrapper[] SelectEntities(CommandMessage dsCommandMessage)
        {
            DispatchWrapper[] selectedEntities = null;

            //Prompt for multiple selection of entities
            if (dsCommandMessage.PromptForSelection(false, "Specify entities", "It is not an entity"))
            {
                //Get selection manager
                SelectionManager dsSelectionMgr = dsDoc.GetSelectionManager();

                //Get count of selected entities
                dsSelectionSetType_e selectionType = dsSelectionSetType_e.dsSelectionSetType_Previous;
                int count = dsSelectionMgr.GetSelectedObjectCount(selectionType);
                if (count > 0)
                {
                    selectedEntities = new DispatchWrapper[count];
                    for (int index = 0; index < count; ++index)
                    {
                        dsObjectType_e entityType;
                        selectedEntities[index] = new DispatchWrapper(dsSelectionMgr.GetSelectedObject(selectionType, index, out entityType));
                    }
                }
            }

            return selectedEntities;
        }

        private static DraftSight.Application ConnectToDraftSight()
        {
            DraftSight.Application dsApp = null;

            try
            {
                //Connect to DraftSight
                dsApp = (DraftSight.Application)Marshal.GetActiveObject("DraftSight.Application");
            }
            catch (Exception ex)
            {
                MessageBox.Show("Failed to connect to DraftSight. Cause: " + ex.Message);
                dsApp = null;
            }

            return dsApp;
        }
    }
}