ArcGIS AO 之投影坐标系的示例，点的投影ProjectPoint

在Arcgis Java SDK中，有许多例子，对于一个地图来讲，坐标系（空间参考）是非常重要的，他直接决定了一个点的坐标值是什么！所以这个示例是很基础的！特此粘贴

这个示例就是ProjectPoint 是Geometry中的示例，几何处理。一下省略了Engine的init和关闭，需要Engine和ArcView许可。

  System.out.println("Starting ProjectPoint - An ArcObjects Java SDK Developer Sample");
            // Create a point with Geographic coordinates...
            Point point = new Point();
            point.putCoords(-100.0, 40.0);

            System.out.println("Original coordinates: " + point.getX() + "," + point.getY());

            // Create the SpatialReferenceEnvironment...
            SpatialReferenceEnvironment spatialReferenceEnvironment = new SpatialReferenceEnvironment();

            // Apply the initial spatial reference...
            ISpatialReference geographicCoordinateSystem = spatialReferenceEnvironment
                    .createGeographicCoordinateSystem(esriSRGeoCSType.esriSRGeoCS_NAD1927);
            point.setSpatialReferenceByRef(geographicCoordinateSystem);

            // Create the output projected coordinate system...
            ISpatialReference projectedCoordinateSystem = spatialReferenceEnvironment
                    .createProjectedCoordinateSystem(esriSRProjCSType.esriSRProjCS_NAD1983UTM_13N);

            // Create the GeoTransformation...
            IGeoTransformation iGeoTransformation = (IGeoTransformation) spatialReferenceEnvironment
                    .createGeoTransformation(esriSRGeoTransformationType.esriSRGeoTransformation_NAD1927_To_WGS1984_5);

            // Project the point...
            point.projectEx(projectedCoordinateSystem, esriTransformDirection.esriTransformForward, iGeoTransformation,
                    false, 0.0, 0.0);
            System.out.println("Projected coordinates: " + point.getX() + " , " + point.getY());

            System.out.println("Done!");

比较重要的坐标系就是WGS1984和中国特有的beijing1954和xian1980，在esriSRGeoCSType中没有xian的关键字，有俩GRS1980和OSSN1980不知道是不是

com.esri.arcgis.geometry.esriSRGeoCSType.esriSRGeoCS_Beijing1954= 4214;

com.esri.arcgis.geometry.esriSRGeoCSType.esriSRGeoCS_WGS1984 =4326;

  public static final int esriSRGeoCS_GRS1980 = 4019;
  public static final int esriSRGeoCS_OSSN1980 = 4279;

 在esriSRPrjCSType中也有相关的坐标系的代码。