空间参考（三）ArcGIS Engine的支持

空间参考（三）-ArcGIS Engine的支持

上一篇 / 下一篇  2011-08-30 22:24:59 / 个人分类：ArcGIS Engine之路

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ArcGIS Engine提供了一系列对象供开发者管理GIS系统的坐标系统。对大部分开发者而言了解ProjectedCoordinateSystem,　GeographicCoordinateSystem,　SpatialReference Environment这三个组件类是非常有必要的，对于高级开发者而言，可能需要自定义坐标系统可以使用这些对象Projection,Datum,AngularUnit,Spheriod,PrimeMeridian和GeoTransformation等。

 

 同一坐标系转换

 private IPoint GetpProjectPoint(IPoint pPoint, bool pBool)

        {

            SpatialReferenceEnvironment pSpatialReferenceEnvironemnt = new SpatialReferenceEnvironment();

            ISpatialReference pFromSpatialReference = pSpatialReferenceEnvironemnt.CreateGeographicCoordinateSystem((int)esriSRGeoCS3Type.esriSRGeoCS_Xian1980);//西安80

            ISpatialReference pToSpatialReference = pSpatialReferenceEnvironemnt.CreateProjectedCoordinateSystem((int)esriSRProjCS4Type.esriSRProjCS_Xian1980_3_Degree_GK_Zone_34);//西安80

            if (pBool == true)//球面转平面

            {

               

                IGeometry pGeo = (IGeometry)pPoint;

                pGeo.SpatialReference = pFromSpatialReference;

                pGeo.Project(pToSpatialReference);

                return pPoint;

            }

            else //平面转球面

            {

                IGeometry pGeo = (IGeometry)pPoint;

                pGeo.SpatialReference = pToSpatialReference;

                pGeo.Project(pFromSpatialReference);

                return pPoint;

            }

        }

不同基准面转换（需要转换参数）

public void ProjectExExample()

        {

           

            ISpatialReferenceFactory pSpatialReferenceFactory = new SpatialReferenceEnvironmentClass();

          

          // ISpatialReference pFromCustom = pSpatialReferenceFactory.CreateESRISpatialReferenceFromPRJFile(@"E:\arcgis\Engine\zidingyi.prj");

            IPoint pFromPoint = new PointClass();

            pFromPoint.X = 518950.788;

            pFromPoint.Y = 4335923.97;

            IZAware pZAware = pFromPoint as IZAware;

            pZAware.ZAware = true;

        

            pFromPoint.Z = 958.4791;

           // ((IGeometry)pFromPoint).SpatialReference = pFromCustom;

            //自定义投影WGS84下的北京6度19带。

            ((IGeometry)pFromPoint).SpatialReference = CreateCustomProjectedCoordinateSystem();

            //目标投影

            IProjectedCoordinateSystem projectedCoordinateSystem = pSpatialReferenceFactory.CreateProjectedCoordinateSystem((int)esriSRProjCS4Type.esriSRProjCS_Xian1980_GK_Zone_19);

            //因为目标基准面和原始基准面不在同一个上，所以牵扯到参数转换，我用7参数转换

            ICoordinateFrameTransformation pCoordinateFrameTransformation = new CoordinateFrameTransformationClass();

            pCoordinateFrameTransformation.PutParameters（7个参数略);

            pCoordinateFrameTransformation.PutSpatialReferences(CreateCustomProjectedCoordinateSystem(), projectedCoordinateSystem as ISpatialReference);

        

         

            //投影转换

            IGeometry2 pGeometry = pFromPoint as IGeometry2;

            pGeometry.ProjectEx(projectedCoordinateSystem as ISpatialReference, esriTransformDirection.esriTransformForward, pCoordinateFrameTransformation, false, 0, 0);

      

        }

private IProjectedCoordinateSystem CreateCustomProjectedCoordinateSystem()

        {

            ISpatialReferenceFactory2 pSpatialReferenceFactory = new SpatialReferenceEnvironmentClass();

            IProjectionGEN pProjection = pSpatialReferenceFactory.CreateProjection((int) esriSRProjectionType.esriSRProjection_GaussKruger) as IProjectionGEN;

            IGeographicCoordinateSystem pGeographicCoordinateSystem = pSpatialReferenceFactory.CreateGeographicCoordinateSystem((int)esriSRGeoCSType.esriSRGeoCS_WGS1984);

            ILinearUnit pUnit = pSpatialReferenceFactory.CreateUnit((int)esriSRUnitType.esriSRUnit_Meter) as ILinearUnit;

          

            IParameter[] pParameters = pProjection.GetDefaultParameters();

           

            IProjectedCoordinateSystemEdit pProjectedCoordinateSystemEdit = new ProjectedCoordinateSystemClass();

            object pName = "WGS-BeiJing1954";

            object pAlias = "WGS-BeiJing1954";

            object pAbbreviation = "WGS-BeiJing1954";

            object pRemarks = "WGS-BeiJing1954";

            object pUsage = "Calculate Meter From lat and lon";

            object pGeographicCoordinateSystemObject = pGeographicCoordinateSystem as object;

            object pUnitObject = pUnit as object;

            object pProjectionObject = pProjection as object;

            object pParametersObject = pParameters as object;

            pProjectedCoordinateSystemEdit.Define(ref pName, ref pAlias, ref pAbbreviation, ref pRemarks, ref pUsage, ref pGeographicCoordinateSystemObject, ref pUnitObject,ref pProjectionObject, ref pParametersObject);

            IProjectedCoordinateSystem5 pProjectedCoordinateSystem = pProjectedCoordinateSystemEdit as IProjectedCoordinateSystem5;

            pProjectedCoordinateSystem.FalseEasting = 500000;

            pProjectedCoordinateSystem.LatitudeOfOrigin = 0;

            pProjectedCoordinateSystem.set_CentralMeridian(true,111);

            pProjectedCoordinateSystem.ScaleFactor=1;

            pProjectedCoordinateSystem.FalseNorthing=0;

            return pProjectedCoordinateSystem;

        }