SkylineGlobe 6.5 如何实现简单多边形的动态绘制 C#示例代码

在Skyline的TEPro软件中，我们可以很容易地绘制出多边形。

那么，在二次开发过程中，该如何绘制一个简单的多边形呢？

通过下面的示例代码，我们可以很容易完成这一项工作。

其中，重点需要了解Geometry对象的定义和使用。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using TerraExplorerX;

namespace HelloSkyline
{
    public partial class CTerrainPolygon: Form
    {
        SGWorld65 sgworld = null;
        String pbhander = "";        
        ITerrainPolygon65 pITPolygon = null;
        List<double> ListVerticsArray = new List<double>();

        public CTerrainPolygon()
        {
            InitializeComponent();

            sgworld = new SGWorld65();
            sgworld.OnLButtonDown += new _ISGWorld65Events_OnLButtonDownEventHandler(sgworld_OnLButtonDown);
            sgworld.OnRButtonDown += new _ISGWorld65Events_OnRButtonDownEventHandler(sgworld_OnRButtonDown);
        }

        bool sgworld_OnRButtonDown(int Flags, int X, int Y)
        {
            sgworld.Window.SetInputMode(MouseInputMode.MI_FREE_FLIGHT);
            pbhander = "";
            pITPolygon = null;            
            return true;
        }

        bool sgworld_OnLButtonDown(int Flags, int X, int Y)
        {
            IWorldPointInfo65 pIWPInfo = sgworld.Window.PixelToWorld(X, Y, WorldPointType.WPT_TERRAIN);
            IPosition65 pIPosition = sgworld.Navigate.GetPosition(AltitudeTypeCode.ATC_ON_TERRAIN);

            if (pbhander == "TerrainPolygon")
            {
                if (pITPolygon == null)
                {
                    ILinearRing cRing = null;
                    double[] cVerticesArray = null;
                    cVerticesArray = new double[] {
                        pIPosition.X,  pIPosition.Y,  0, 
                        pIWPInfo.Position.X,  pIWPInfo.Position.Y,  pIWPInfo.Position.Distance,  
                        pIWPInfo.Position.X,  pIWPInfo.Position.Y,  pIWPInfo.Position.Distance,                         
                            };
                    cRing = sgworld.Creator.GeometryCreator.CreateLinearRingGeometry(cVerticesArray);
                    
                    uint nLineColor = 0xFF00FF00;
                    uint nFillColor = 0x7FFF0000;
                    AltitudeTypeCode eAltitudeTypeCode = AltitudeTypeCode.ATC_ON_TERRAIN;
                    string gid = CreateGroup("AnalysisTEMP");
                    pITPolygon = sgworld.Creator.CreatePolygon(cRing, nLineColor, nFillColor, eAltitudeTypeCode, gid, "Polygon");

                    IPolygon polygonGeometry = pITPolygon.Geometry as IPolygon;
                    polygonGeometry.StartEdit();
                    foreach (ILinearRing ring in polygonGeometry.Rings)
                    {
                        double dx = pIWPInfo.Position.X;
                        double dy = pIWPInfo.Position.Y;
                        double dh = pIWPInfo.Position.Distance;                        
                        ring.Points.AddPoint(dx, dy, dh);
                        ring.Points.DeletePoint(0);
                    }
                    IGeometry editedGeometry = polygonGeometry.EndEdit();
                    pITPolygon.Geometry = editedGeometry;                
                }
                else
                {
                    IPolygon polygonGeometry = pITPolygon.Geometry as IPolygon;
                    polygonGeometry.StartEdit();
                    foreach (ILinearRing ring in polygonGeometry.Rings)
                    {
                        double dx = pIWPInfo.Position.X;
                        double dy = pIWPInfo.Position.Y;
                        double dh = pIWPInfo.Position.Distance;
                        ring.Points.AddPoint(dx, dy, dh);
                    }
                    IGeometry editedGeometry = polygonGeometry.EndEdit();
                    pITPolygon.Geometry = editedGeometry;                    
                }
            }
            return false;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            pbhander = "TerrainPolygon";
            sgworld.Window.SetInputMode(MouseInputMode.MI_COM_CLIENT);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string gid = sgworld.ProjectTree.FindItem("AnalysisTEMP");
            if (gid != null && gid != "")
            {
                sgworld.ProjectTree.DeleteItem(gid);
            }
        }

        private String CreateGroup(String GroupName)
        {
            string gid = sgworld.ProjectTree.FindItem(GroupName);
            if (gid != null && gid != "")
            {
                return gid;
            }
            else
            {
                return sgworld.ProjectTree.CreateLockedGroup(GroupName);
            }            
        }
    }
}