Engine中如何进行七参数投影转换？

private void func1ToolStripMenuItem_Click(object sender, EventArgs e) 

{ 

Type t = Type.GetTypeFromProgID(esriGeometry.SpatialReferenceEnvironment); 

System.Object obj = Activator.CreateInstance(t); 

ISpatialReferenceFactory srFact = obj as ISpatialReferenceFactory; 

IGeographicCoordinateSystem wgs84GCS = srFact.CreateGeographicCoordinateSystem((int)esriSRGeoCSType.esriSRGeoCS_WGS1984); 

IProjectedCoordinateSystem xian80PCS = srFact.CreateProjectedCoordinateSystem((int)esriSRProjCS4Type.esriSRProjCS_Xian1980_3_Degree_GK_CM_102E); 



IGeoTransformation geoTrans = CreateGeoTransformation((ISpatialReference)wgs84GCS, (ISpatialReference)xian80PCS); 



IWorkspaceFactory wksfac = new FileGDBWorkspaceFactoryClass(); 

IFeatureWorkspace feawks = wksfac.OpenFromFile(@E:TEST.gdb,0) as IFeatureWorkspace; 

IFeatureClass fc = feawks.OpenFeatureClass(POINT); 

IFeature fea = fc.Search(null, false).NextFeature(); 

IGeometry5 geometry; 

IPoint point = fea.ShapeCopy as IPoint; 

geometry = point as IGeometry5; 

geometry.SpatialReference = wgs84GCS; 



geometry.ProjectEx(xian80PCS, esriTransformDirection.esriTransformForward, geoTrans, false, 0.0, 0.0); 

point = geometry as IPoint; 

MessageBox.Show(point.X.ToString(),point.Y.ToString()); 

} 



private IGeoTransformation CreateGeoTransformation(ISpatialReference pInputSR, ISpatialReference pOutputSR) 

{ 

IGeoTransformation pGeoTrans; 

pGeoTrans = new CoordinateFrameTransformationClass(); 



((ICoordinateFrameTransformation)pGeoTrans).PutSpatialReferences(pInputSR, pOutputSR); 

((ICoordinateFrameTransformation)pGeoTrans).PutParameters(p1, p2, p3, p4, p5, p6, p7); 



return pGeoTrans; 

}