MarkPoints.cs

This example demonstrates how to how to add markers for the points of interest. The marker represented by image loaded from the file will be added on the mouse down event. The markers will be stored in the temporary in-memory shapefile. Here is a screenshot with the results of the code execution.

using System.IO;
using System.Windows.Forms;
using AxMapWinGIS;
using MapWinGIS;
 
namespace Examples
{
    public partial class MapExamples
    {
        // the handle of the layer with markers
        private int m_layerHandle = -1;
    
        // <summary>
        // Loads the layers and registers event handlers
        // </summary>
        public void MarkPoints(AxMap axMap1, string dataPath)
        {
            axMap1.Projection = tkMapProjection.PROJECTION_GOOGLE_MERCATOR;
 
            string filename = dataPath + "buildings.shp";
            if (!File.Exists(filename))
            {
                MessageBox.Show("Couldn't file the file: " + filename);
                return;
            }
 
            var sf = new Shapefile();
            sf.Open(filename, null);
            m_layerHandle = axMap1.AddLayer(sf, true);
            sf = axMap1.get_Shapefile(m_layerHandle);     // in case a copy of shapefile was created by GlobalSettings.ReprojectLayersOnAdding
 
            sf = new Shapefile();
            if (!sf.CreateNewWithShapeID("", ShpfileType.SHP_POINT))
            {
                MessageBox.Show("Failed to create shapefile: " + sf.ErrorMsg[sf.LastErrorCode]);
                return;
            }
 
            m_layerHandle = axMap1.AddLayer(sf, true);
 
            ShapeDrawingOptions options = sf.DefaultDrawingOptions;
            options.PointType = tkPointSymbolType.ptSymbolPicture;
            options.Picture = this.OpenMarker(dataPath);
            sf.CollisionMode = tkCollisionMode.AllowCollisions;
 
            axMap1.SendMouseDown = true;
            axMap1.CursorMode = tkCursorMode.cmNone;
            MapEvents.MouseDownEvent += AxMap1MouseDownEvent;   // change MapEvents to axMap1
        }
 
        // <summary>
        // Opens a marker from the file
        // </summary>
        private Image OpenMarker(string dataPath)
        {
            string path = Path.GetDirectoryName(Application.ExecutablePath) + @"..\..\..\..\icons\marker.png";
            if (!File.Exists(path))
            {
                MessageBox.Show("Can't find the file: " + path);
            }
            else
            {
                Image img = new Image();
                if (!img.Open(path, ImageType.USE_FILE_EXTENSION, true, null))
                {
                    MessageBox.Show(img.ErrorMsg[img.LastErrorCode]);
                    img.Close();
                }
                else
                    return img;
            }
            return null;
        }
 
        // <summary>
        // Handles mouse down event and adds the marker
        // </summary>
        public void AxMap1MouseDownEvent(object sender, _DMapEvents_MouseDownEvent e)
        {
            if (e.button == 1)          // left button
            {
                Shapefile sf = axMap1.get_Shapefile(m_layerHandle);
 
                Shape shp = new Shape();
                shp.Create(ShpfileType.SHP_POINT);
 
                Point pnt = new Point();
                double x = 0.0;
                double y = 0.0;
                axMap1.PixelToProj(e.x, e.y, ref x, ref y);
                pnt.x = x;
                pnt.y = y;
                int index = shp.numPoints;
                shp.InsertPoint(pnt, ref index);
 
                index = sf.NumShapes;
                if (!sf.EditInsertShape(shp, ref index))
                {
                    MessageBox.Show("Failed to insert shape: " + sf.ErrorMsg[sf.LastErrorCode]);
                    return;
                }
                axMap1.Redraw();
            }
        }
    }
}