ArcGIS.Server.9.2.DotNet自带例子分析（一、四）

目的：
1.距离测量功能。
准备：
1.（一、三）的工程，具体见前篇。
开始：
1.新建名为Measure.ascx的用户控件,并且实现ICallbackEventHandler接口，具体代码如下：

 1namespace MappingApp
 2{
 3    public partial class Measure : System.Web.UI.UserControl, ICallbackEventHandler
 4    {
 5        protected void Page_Load(object sender, EventArgs e)
 6        {
 7
 8        }
 9
        ICallbackEventHandler 成员#region ICallbackEventHandler 成员

        //负责把结果回传给客户端
        public string GetCallbackResult()
        {
            throw new Exception("The method or operation is not implemented.");
        }

        //负责从客户端javascript传来的参数
        public void RaiseCallbackEvent(string eventArgument)
        {
            throw new Exception("The method or operation is not implemented.");
        }

        #endregion
    }
}

2. 加入具体的线距离测量和面积测量功能代码，具体的代码和说明如下：

  1namespace MappingApp
  2{
  3    //地图单位
  4    public enum MapUnit
  5    {
  6        Resource_Default, Degrees, Feet, Meters //默认，度，码，米
  7    }
  8
  9    //测量单位
 10    public enum MeasureUnit
 11    {
 12        Feet, Kilometers, Meters, Miles //码，千米，米，英里
 13    }
 14
 15    //区域单位
 16    public enum AreaUnit
 17    {
 18        Acres, Sq_Feet, Sq_Kilometers, Sq_Meters, Sq_Miles //英亩，平方码，平方千米，平方米，平方英里
 19    }
 20
 21    public partial class Measure : System.Web.UI.UserControl, ICallbackEventHandler
 22    {
 23        MapResourceManager m_resourceManger;
 24        IMapFunctionality m_mapFunctionality;
 25        //页面
 26        private Page m_page;
 27        //客户端代码段
 28        public string m_callbackInvocation = "";
 29        //地图控件ID
 30        private string m_mapBuddyId = "Map1";
 31        //用户控件id
 32        public string m_id;
 33        //地图控件
 34        private Map m_map;
 35        //默认地图单位
 36        private MapUnit m_FallbackMapUnit = MapUnit.Degrees; 
 37        private MapUnit m_mapUnits;
 38        //
 39        private MapUnit m_startMapUnits = MapUnit.Degrees;
 40        //默认测量单位
 41        public MeasureUnit m_measureUnits = MeasureUnit.Miles;
 42        //默认区域单位
 43        public AreaUnit m_areaUnits = AreaUnit.Sq_Miles;
 44        //数字精确到4位
 45        private double m_numberDecimals = 4;
 46
 47        protected void Page_Load(object sender, EventArgs e)
 48        {
 49            //控件id
 50            m_id = this.ClientID;
 51            //页面
 52            m_page = this.Page;
 53            if (m_mapBuddyId == null || m_mapBuddyId.Length == 0)
 54            {
 55                m_mapBuddyId = "Map1";
 56            }
 57            //获取map控件
 58            m_map = m_page.FindControl(m_mapBuddyId) as Map;
 59            //获取MapResourceManager控件
 60            m_resourceManger = m_page.FindControl(m_map.MapResourceManager) as MapResourceManager;
 61            //通过GetCallbackEventReference生成客户端调用的javascript方法段
 62            m_callbackInvocation = m_page.ClientScript.GetCallbackEventReference(this, "argument", "processCallbackResult", "context", true);
 63        }
 64
 65        //
 66        protected void Page_PreRender(object sender, EventArgs e)
 67        {
 68            GetMeasureResource();
 69        }
 70
 71        private void GetMeasureResource()
 72        {
 73            string primeResource = m_map.PrimaryMapResource;
 74            IEnumerable mapResources = m_resourceManger.GetResources();
 75            IEnumerator resEnum = mapResources.GetEnumerator();
 76           
 77            resEnum.MoveNext();
 78
 79            IGISResource resource;
 80            if (primeResource != null && primeResource.Length > 0)
 81            {
 82                resource = m_resourceManger.GetResource(primeResource);
 83            }
 84            else
 85            {
 86                resource = resEnum.Current as IGISResource;
 87            }
 88
 89            if (resource != null)
 90            {
 91                m_mapFunctionality = (IMapFunctionality)resource.CreateFunctionality(typeof(IMapFunctionality), "mapFunctionality");
 92            }
 93        }
 94
 95        ICallbackEventHandler 成员#region ICallbackEventHandler 成员
 96        private string _callbackArg;
 97        //负责把结果回传给客户端
 98        string ICallbackEventHandler.GetCallbackResult()
 99        {
            return RaiseCallbackEvent(_callbackArg);
        }

        //负责从客户端javascript传来的参数
        void ICallbackEventHandler.RaiseCallbackEvent(string eventArgument)
        {
            _callbackArg = eventArgument;
        }

        //具体处理
        private string RaiseCallbackEvent(string requestString)
        {
            //对请求字符串进行拆分添加到NameValueCollection m_queryString中
            Array keyValuePairs = requestString.Split("&".ToCharArray());
            NameValueCollection m_queryString = new NameValueCollection();
            string[] keyValue;
            string response = "";

            if (keyValuePairs.Length > 0)
            {
                for (int i = 0; i < keyValuePairs.Length; i++)
                {
                    keyValue = keyValuePairs.GetValue(i).ToString().Split("=".ToCharArray());
                    m_queryString.Add(keyValue[0], keyValue[1]);
                }
            }
            else
            {
                keyValue = requestString.Split("=".ToCharArray());
                if (keyValue.Length > 0)
                {
                    m_queryString.Add(keyValue[0], keyValue[1]);
                }
                    
            }
            //控件类型
            string controlType = m_queryString["ControlType"];
            //参数
            string eventArg = m_queryString["EventArg"];
            if (controlType == null)
            {
                controlType = "Map";
            }

            switch (controlType)
            {
                case "Map":
                    string vectorMode = m_queryString["VectorMode"];
                    if (vectorMode != null && vectorMode.ToLower() == "measure")
                    {
                        //输出测量结果内容
                        response = ProcessMeasureRequest(m_queryString);
                    }
                    break;
                default:
                    break;
            }

            //结果内容返回给客户端
            return response;
        }

        #endregion

        //根据请求字符串进行不同的测量
        public string ProcessMeasureRequest(NameValueCollection queryString)
        {
            if (m_mapFunctionality == null)
            {
                GetMeasureResource();
            }
            object o = Session["MeasureMapUnits"];
            if (o != null)
            {
                m_mapUnits = (MapUnit)Enum.Parse(typeof(MapUnit), o.ToString());
            }
            else if (m_startMapUnits == MapUnit.Resource_Default)
            {
                //获取默认地图单位
                m_mapUnits = GetResourceDefaultMapUnit();
            }
            else
            {
                m_mapUnits = m_startMapUnits;
            }

            //请求参数
            string eventArg = queryString["EventArg"].ToLower();
            string vectorAction = queryString["VectorAction"].ToLower();
            string[] coordPairs, xys;
            //坐标字符串
            string coordString = queryString["coords"];
            if (coordString == null && coordString.Length == 0)
            {
                coordString = "";
            }
            //坐标字符串分割
            coordPairs = coordString.Split(char.Parse("|"));
            //地图单位
            string mapUnitString = queryString["MapUnits"];
            if (mapUnitString != null && mapUnitString.Length > 0)
            {
                m_mapUnits = (MapUnit)Enum.Parse(typeof(MapUnit), mapUnitString);
            }
            Session["MeasureMapUnits"] = m_mapUnits;
            //测量单位
            string measureUnitString = queryString["MeasureUnits"];
            if (measureUnitString != null && measureUnitString.Length > 0)
            {
                m_measureUnits = (MeasureUnit)Enum.Parse(typeof(MeasureUnit), measureUnitString);
            }
            //区域单位
            string areaUnitstring = queryString["AreaUnits"];
            if (areaUnitstring != null && areaUnitstring.Length > 0)
            {
                m_areaUnits = (AreaUnit)Enum.Parse(typeof(AreaUnit), areaUnitstring);
            }

            //输出内容字符串
            string response = "";
            PointCollection points = new PointCollection();
            PointCollection dPoints = new PointCollection();
            ArrayList distances = new ArrayList();
            double totalDistance = 0;
            double segmentDistance = 0;
            double area = 0;
            double perimeter = 0;
            double roundFactor = Math.Pow(10, m_numberDecimals);
            double xD, yD, tempDist, tempDist2, tempArea, x1, x2, y1, y2;

            //动作为添加点
            if (vectorAction == "addpoint")
            {
                //坐标点大于1个时，就是保证是一条线
                if (coordPairs != null && coordPairs.Length > 1)
                {
                    for (int i = 0; i < coordPairs.Length; i++)
                    {
                        xys = coordPairs[i].Split(char.Parse(":"));
                        //像素坐标转换成地理坐标
                        points.Add(Point.ToMapPoint(Convert.ToInt32(xys[0]), Convert.ToInt32(xys[1]), m_map.GetTransformationParams(ESRI.ArcGIS.ADF.Web.Geometry.TransformationDirection.ToMap)));

                        if (i > 0)//第二个坐标点的时候
                        {
                            if (m_mapUnits == MapUnit.Degrees)//地图单位为度的时候
                            {
                                //计算与前一个点的距离，分段距离
                                tempDist = DegreeToFeetDistance(points[i - 1].X, points[i - 1].Y, points[i].X, points[i].Y);
                                //度转成码
                                y1 = DegreeToFeetDistance(points[i].X, points[i].Y, points[i].X, 0);
                                //度转成码
                                x1 = DegreeToFeetDistance(points[i].X, points[i].Y, 0, points[i].Y);
                                dPoints.Add(new Point(x1, y1));
                                //单位换算
                                segmentDistance = ConvertUnits(tempDist, MapUnit.Feet, m_measureUnits);
                            }
                            else//地图单位为米的时候
                            {
                                xD = Math.Abs(points[i].X - points[i - 1].X);
                                yD = Math.Abs(points[i].Y - points[i - 1].Y);
                                //计算2个坐标之间的距离
                                tempDist = Math.Sqrt(Math.Pow(xD, 2) + Math.Pow(yD, 2));
                                //单位换算
                                segmentDistance = ConvertUnits(tempDist, m_mapUnits, m_measureUnits);

                            }

                            //把分段距离添加到distances
                            distances.Add(segmentDistance);
                            //计算总距离
                            totalDistance += segmentDistance;
                            //只显示4位小数
                            segmentDistance = Math.Round(segmentDistance * roundFactor) / roundFactor;
                            totalDistance = Math.Round(totalDistance * roundFactor) / roundFactor;
                        }
                        else//第一个坐标点的时候
                        {
                            if (m_mapUnits == MapUnit.Degrees)
                            {
                                //度转成码
                                y1 = DegreeToFeetDistance(points[i].X, points[i].Y, points[i].X, 0);
                                x1 = DegreeToFeetDistance(points[i].X, points[i].Y, 0, points[i].Y);
                                dPoints.Add(new Point(x1, y1));
                            }
                        }
                    }
                }

                //为多边形时
                if (eventArg == "polygon")
                {
                    if (points.Count > 2)
                    {
                        if (m_mapUnits == MapUnit.Degrees)
                        {
                            //最后一段的距离计算
                            tempDist = DegreeToFeetDistance(points[points.Count - 1].X, points[points.Count - 1].Y, points[0].X, points[0].Y);
                            tempDist2 = ConvertUnits(tempDist, MapUnit.Feet, m_measureUnits);
                            distances.Add(tempDist2);
                            //加入第一点作为多边形的结束节点
                            dPoints.Add(dPoints[0]);
                        }
                        else
                        {
                            //最后一段的距离计算
                            xD = Math.Abs(points[points.Count - 1].X - points[0].X);
                            yD = Math.Abs(points[points.Count - 1].Y - points[0].Y);
                            tempDist = Math.Sqrt(Math.Pow(xD, 2) + Math.Pow(yD, 2));
                            tempDist2 = ConvertUnits(tempDist, m_mapUnits, m_measureUnits);
                            distances.Add(tempDist2);
                        }
                        //加入第一点作为多边形的结束节点
                        points.Add(points[0]);
                        //总长度+最后一段长度
                        perimeter = totalDistance + tempDist2;
                        //多边形面积计算
                        tempArea = 0;
                        MapUnit mUnits = m_mapUnits;
                        for (int j = 0; j < points.Count - 1; j++)
                        {
                            if (m_mapUnits == MapUnit.Degrees)
                            {
                                x1 = Convert.ToDouble(dPoints[j].X);
                                x2 = Convert.ToDouble(dPoints[j + 1].X);
                                y1 = Convert.ToDouble(dPoints[j].Y);
                                y2 = Convert.ToDouble(dPoints[j + 1].Y);
                                mUnits = MapUnit.Feet;
                            }
                            else
                            {
                                x1 = Convert.ToDouble(points[j].X);
                                x2 = Convert.ToDouble(points[j + 1].X);
                                y1 = Convert.ToDouble(points[j].Y);
                                y2 = Convert.ToDouble(points[j + 1].Y);
                            }
                            //tempArea += tempArea + (x1 + x2) * (y1 - y2);
                            double xDiff = x2 - x1;
                            double yDiff = y2 - y1;
                            tempArea += x1 * yDiff - y1 * xDiff;
                        }
                        tempArea = Math.Abs(tempArea) / 2;
                        //单位换算
                        area = ConvertAreaUnits(tempArea, mUnits, m_areaUnits);
                        //保留4位小数
                        perimeter = Math.Round(perimeter * roundFactor) / roundFactor;
                        area = Math.Round(area * roundFactor) / roundFactor;

                        //输出显示内容html
                        response = String.Format("<table cellspacing='0'  ><tr><td>Perimeter: </td><td align='right'>{0}</td><td>{1}</td></tr><tr><td>Area:</td><td  align='right'>{2}</td><td>{3}</td></tr></table>", perimeter, WriteMeasureUnitDropdown(), area, WriteAreaUnitDropdown());
                    }
                    else
                    {
                        //输出显示内容html,小于3个点时候
                        response = String.Format("<table cellspacing='0' ><tr><td>Perimeter: </td><td align='right'> 0</td><td>{0}</td></tr><tr><td>Area:</td><td align='right'>0 </td><td>{1}</td></tr></table>", WriteMeasureUnitDropdown(), WriteAreaUnitDropdown());
                    }
                }
                else
                {
                    //输出显示内容html,为线的时候
                    response = String.Format("<table cellspacing='0' ><tr><td>Segment: </td><td align='right'>{0} </td><td>{1}</td></tr><tr><td>Total Length:</td><td align='right'>{2} </td><td>{3}</td></tr></table>", segmentDistance, m_measureUnits.ToString(), totalDistance, WriteMeasureUnitDropdown());
                }

            }
            //动作为获取坐标
            else if (vectorAction == "coordinates")
            {
                xys = coordPairs[0].Split(char.Parse(":"));
                Point coordPoint = Point.ToMapPoint(Convert.ToInt32(xys[0]), Convert.ToInt32(xys[1]), m_map.GetTransformationParams(ESRI.ArcGIS.ADF.Web.Geometry.TransformationDirection.ToMap));

                //输出坐标的html显示内容
                response = String.Format("<table cellspacing='0' ><tr><td>X Coordinate:</td><td align='right'>{0}</td></tr><tr><td>Y Coordinate:</td><td align='right'>{1}</td></tr></table>", (Math.Round(coordPoint.X * roundFactor) / roundFactor).ToString(), (Math.Round(coordPoint.Y * roundFactor) / roundFactor).ToString());
            }
            //动作为结束画线
            else if (vectorAction == "finish")
            {
                response = "Shape complete";
            }

            //把结果内容返回给客户端
            return String.Format("measure:::{0}:::{1}:::{2}", m_id, vectorAction, response);
        }

        //输出测量单位选择下拉框
        public string WriteMeasureUnitDropdown()
        {
            System.Text.StringBuilder sb = new System.Text.StringBuilder();
            sb.Append("<select id=\"MeasureUnits2\" onchange=\"changeMeasureUnits()\" style=\"font: normal 7pt Verdana; width: 100px;\">");
            Array mArray = Enum.GetValues(typeof(MeasureUnit));
            foreach (MeasureUnit mu in mArray)
            {
                sb.AppendFormat("<option value=\"{0}\" {1}>{0}</option>", mu.ToString(), CheckFormMeasureUnits(mu.ToString()));

            }
            sb.Append("</select>");

            return sb.ToString();
        }

        //检查默认选中项
        public string CheckFormMeasureUnits(string unit)
        {
            string response = "";
            if (unit == m_measureUnits.ToString())
                response = "selected=\"selected\"";
            return response;
        }

        //输出测量单位选择下拉框
        public string WriteAreaUnitDropdown()
        {
            System.Text.StringBuilder sb = new System.Text.StringBuilder();
            sb.Append("<select id=\"AreaUnits2\" onchange=\"changeAreaUnits()\" style=\"font: normal 7pt Verdana; width: 100px;\">");
            Array aArray = Enum.GetValues(typeof(AreaUnit));
            foreach (AreaUnit au in aArray)
            {
                sb.AppendFormat("<option value=\"{0}\" {1}>{0}</option>", au.ToString(), CheckFormAreaUnits(au.ToString()));

            }
            sb.Append("</select>");

            return sb.ToString();
        }

        //检查默认选中项
        public string CheckFormAreaUnits(string unit)
        {
            string response = "";
            if (unit == m_areaUnits.ToString())
                response = "selected=\"selected\"";
            return response;
        }

        //面积单位换算
        private double ConvertAreaUnits(double area, MapUnit baseUnits, AreaUnit toUnits)
        {
            double mArea = area;
            if (baseUnits == MapUnit.Feet)
            {
                if (toUnits == AreaUnit.Acres)
                    mArea = area * 0.000022956;
                else if (toUnits == AreaUnit.Sq_Meters)
                    mArea = area * 0.09290304;
                else if (toUnits == AreaUnit.Sq_Miles)
                    mArea = area * 0.00000003587;
                else if (toUnits == AreaUnit.Sq_Kilometers)
                    mArea = area * 0.09290304 / 1000000;
            }
            else if (baseUnits == MapUnit.Meters)
            {
                if (toUnits == AreaUnit.Acres)
                    mArea = area * 0.0002471054;
                else if (toUnits == AreaUnit.Sq_Miles)
                    mArea = area * 0.0000003861003;
                else if (toUnits == AreaUnit.Sq_Kilometers)
                    mArea = area * 1.0e-6;
                else if (toUnits == AreaUnit.Sq_Feet)
                    mArea = area * 10.76391042;
            }

            return mArea;
        }

        //单位换算
        public double ConvertUnits(double distance, MapUnit fromUnits, MeasureUnit toUnits)
        {
            double mDistance = distance;
            if (fromUnits == MapUnit.Feet)
            {
                if (toUnits == MeasureUnit.Miles)
                {
                    mDistance = distance / 5280;
                }
                else if (toUnits == MeasureUnit.Meters)
                {
                    mDistance = distance * 0.304800609601;
                }
                else if (toUnits == MeasureUnit.Kilometers)
                {
                    mDistance = distance * 0.0003048;
                }
            }
            else
            {
                if (toUnits == MeasureUnit.Miles)
                {
                    mDistance = distance * 0.0006213700922;
                }
                else if (toUnits == MeasureUnit.Feet)
                {
                    mDistance = distance * 3.280839895;
                }
                else if (toUnits == MeasureUnit.Kilometers)
                {
                    mDistance = distance / 1000;
                }
            }
            return mDistance;
        }

        //度转成码距离
        private double DegreeToFeetDistance(double x1, double y1, double x2, double y2)
        {
            double Lat1 = DegToRad(y1);
            double Lat2 = DegToRad(y2);
            double Lon1 = DegToRad(x1);
            double Lon2 = DegToRad(x2);
            double LonDist = Lon1 - Lon2;
            double LatDist = Lat1 - Lat2;
            double x = Math.Pow(Math.Sin(LatDist / 2), 2) + Math.Cos(Lat1) * Math.Cos(Lat2) * Math.Pow(Math.Sin(LonDist / 2), 2);
            x = 2 * Math.Asin(Math.Min(1, Math.Sqrt(x)));
            x = (3963 - 13 * Math.Sin((Lat1 + Lat2) / 2)) * x;
            // in miles convert to feet and use that as base
            return (x * 5280);
        }

        //度转成弧度
        private double DegToRad(double degrees)
        {
            return Convert.ToDouble(degrees * Math.PI / 180);
        }

        private MapUnit GetResourceDefaultMapUnit()
        {
            MapUnit mUnit = MapUnit.Degrees;
            try
            {
                //获取地图资源单位
                Units mu = m_mapFunctionality.Units;
                if (mu == Units.DecimalDegrees)
                {
                    mUnit = MapUnit.Degrees;
                }  
                else if (mu == Units.Feet)
                {
                    mUnit = MapUnit.Feet;
                }
                else if (mu == Units.Meters)
                {
                    mUnit = MapUnit.Meters;
                }
                    
            }
            catch
            {
                //不能获取地图资源单位时用m_FallbackMapUnit定义的单位
                mUnit = m_FallbackMapUnit;
            }
            return mUnit;

        }

        public string Id
        {
            get { return m_id; }
            set { m_id = value; }
        }

        private string ClientCallbackInvocation
        {
            get { return m_callbackInvocation; }
            set { m_callbackInvocation = value; }
        }

        private MapResourceManager MapResourceManager
        {
            get { return m_resourceManger; }
            set { m_resourceManger = value; }
        }

        /**//// <summary>
        /// Id of Buddy MapControl
        /// </summary>
        public string MapBuddyId
        {
            get { return m_mapBuddyId; }
            set { m_mapBuddyId = value; }
        }


        /**//// <summary>
        /// Unit used resource. Resource_Default will return value from resource, if available. Other values will force calculations to use that unit.
        /// </summary>
        public MapUnit MapUnits
        {
            get { return m_startMapUnits; }
            set { m_startMapUnits = value; }
        }

        /**//// <summary>
        ///  Unit used in display of linear measurements.
        /// </summary>
        public MeasureUnit MeasureUnits
        {
            get { return m_measureUnits; }
            set { m_measureUnits = value; }
        }

        /**//// <summary>
        ///  Area Units - Unit used in display of area measurements.
        /// </summary>
        public AreaUnit AreaUnits
        {
            get { return m_areaUnits; }
            set { m_areaUnits = value; }
        }

        // Number of Decimals - Number of decimal digits displayed in measurements.
        public double NumberDecimals
        {
            get { return m_numberDecimals; }
            set { m_numberDecimals = value; }
        }


        public override bool Visible
        {
            get { return base.Visible; }
        }

        public override bool EnableTheming
        {
            get
            {
                return base.EnableTheming;
            }
        }

        public override bool EnableViewState
        {
            get
            {
                return base.EnableViewState;
            }
        }

    }
}

3.代码贴太多了编辑器死掉了一样了，郁闷换个新篇继续写了...