ArcGis空间分析之剖面图

       剖面图，就是在具有高程值的raster上画一条直线，这条直线上的每个点除了x,y坐标为更具附加了高程值，便可画出高程值随直线的一个曲线图。高程值只是一个最简单的例子，当raster不是以高程值而是以某个我们想要的值来渲染的时候，这条曲线图便表达的是，随直线变化而变化的某个值的曲线图，开始做这个的时候遇到了一些无法解释的困难，如Com组件错误等，这里参考了韩鹏的<<ArcObject方法>>，这里推荐一下，这是本好书，值得拥有啊，以下是我的代码，我用的是ArcgisEngine来做的，不过ArcgisServer也可以实现

       //得到要做剖面分析的面

       IRasterLayer layer = this.axMapControl1.Map.get_Layer(0) as IRasterLayer;

       IRasterSurface rasterSurf = new RasterSurfaceClass();

       rasterSurf.PutRaster(layer.Raster, 0);

       ISurface surface = rasterSurf as ISurface;

       //得到画的直线

       IPolyline inputLine = new PolylineClass();

       IPoint start  = new PointClass();

       start.X = -96.522;

       start.Y = 25.589;

       inputLine.FromPoint = start;

       IPoint end = new PointClass();

       end.X = 1.048;

       end.Y = 28.664;

       inputLine.ToPoint = end;

       //用ISurface的 InterpolateShape方法，得到这条直线做剖面后的Geometry，方法说明详见帮助     

       IGeometry OutShape;

       object size = new object();

       surface.InterpolateShape(inputLine, out OutShape, ref size);

       //将结果QI为 PointCollection，QI成功显示结果是直线上单一的几个离散点，InterpolateShape会自动将分析的结果直线上选取六个等分的离散点，以这六个点的值来作曲线图

       IPointCollection pointCollection = OutShape as IPointCollection;

       IMAware maware = pointCollection as IMAware;

       maware.MAware = true;

       IZAware zaware = pointCollection as IZAware;

       zaware.ZAware = true;

       IMSegmentation mseg = pointCollection as IMSegmentation;

       //设置M的值为距离

       mseg.SetMsAsDistance(false);

       //建立featureClass，为后面曲线图提供数据

       IWorkspaceFactory workspaceFactory = new InMemoryWorkspaceFactoryClass();

       ESRI.ArcGIS.Geodatabase.IWorkspaceName workspaceName = workspaceFactory.Create("", "MyWorkspace", null, 0);

       ESRI.ArcGIS.esriSystem.IName name = (IName)workspaceName;

       ESRI.ArcGIS.Geodatabase.IWorkspace inmemWor = (IWorkspace)name.Open();

       IFields fields = new FieldsClass();

       IFieldsEdit fieldsEdit = fields as IFieldsEdit;

       IField oidField = new FieldClass();

       IFieldEdit oidFieldEdit = oidField as IFieldEdit;

       oidFieldEdit.Name_2 = "OID";

       oidFieldEdit.Type_2 = esriFieldType.esriFieldTypeOID;

       fieldsEdit.AddField(oidField);

       IGeometryDef geometryDef = new GeometryDefClass();

       IGeometryDefEdit geometryDefEdit = geometryDef as IGeometryDefEdit;

       geometryDefEdit.GeometryType_2 = ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPoint;

       geometryDefEdit.HasM_2 = true;

       geometryDefEdit.HasZ_2 = true;

       ISpatialReferenceFactory spatialReferenceFactory = new SpatialReferenceEnvironmentClass();

       ISpatialReference spatialReference =    spatialReferenceFactory.CreateGeographicCoordinateSystem((int)esriSRGeoCSType.esriSRGeoCS_WGS1984);

       ISpatialReferenceResolution spatialReferenceResolution = (ISpatialReferenceResolution)spatialReference;   spatialReferenceResolution.ConstructFromHorizon();

       ISpatialReferenceTolerance spatialReferenceTolerance = (ISpatialReferenceTolerance)spatialReference; spatialReferenceTolerance.SetDefaultXYTolerance();

       geometryDefEdit.SpatialReference_2 = spatialReference;

       IField geometryField = new FieldClass();

       IFieldEdit geometryFieldEdit = (IFieldEdit)geometryField;

       geometryFieldEdit.Name_2 = "Shape";

       geometryFieldEdit.Type_2 = esriFieldType.esriFieldTypeGeometry;

       geometryFieldEdit.GeometryDef_2 = geometryDef;

       fieldsEdit.AddField(geometryField);

       IField mField = new FieldClass();

       IFieldEdit mFieldEdit = (IFieldEdit)mField;

       mFieldEdit.Name_2 = "M";

       mFieldEdit.Type_2 = esriFieldType.esriFieldTypeDouble;

       mFieldEdit.Length_2 = 8;

       fieldsEdit.AddField(mField);

       IField zField = new FieldClass();

       IFieldEdit zFieldEdit = (IFieldEdit)zField;

       zFieldEdit.Name_2 = "Z";

       zFieldEdit.Type_2 = esriFieldType.esriFieldTypeDouble;

       zFieldEdit.Length_2 = 8;

       fieldsEdit.AddField(zField);

       IFieldChecker fieldChecker = new FieldCheckerClass();

       IEnumFieldError enumFieldError = null;

       IFields validatedFields = null;

       fieldChecker.ValidateWorkspace = inmemWor;

       fieldChecker.Validate(fields, out enumFieldError, out validatedFields);

       IFeatureClass featureClass = (inmemWor as IFeatureWorkspace).CreateFeatureClass("test", validatedFields, null, null, esriFeatureType.esriFTSimple, "Shape", "");

       IFeatureCursor cursor = featureClass.Insert(true);

       IFeatureBuffer buffer = featureClass.CreateFeatureBuffer();

       int count = pointCollection.PointCount;

       for (int i = 0; i < count; ++i)

       {

       IPoint p = pointCollection.get_Point(i);

       buffer.Shape = p as IGeometry;

       buffer.set_Value(buffer.Fields.FindField("M"), p.M);

       buffer.set_Value(buffer.Fields.FindField("Z"), p.Z);

       cursor.InsertFeature(buffer);

       }

       cursor.Flush();

       //开始做曲线图

       IFeatureLayer featurelayer = new FeatureLayerClass();

       featurelayer.FeatureClass = featureClass;

       ITable table = featurelayer as ITable;

       IDataGraph datagraph = new DataGraphClass();

       datagraph.Table = table;

       datagraph.FieldSet1 = "Z";

       datagraph.FieldSet2 = "M";

       IDataGraphProperties proper = datagraph as IDataGraphProperties;

       proper.Title = "曲线图";

       proper.SubTitle = "跟据Z和M值做的剖面图";

       proper.GraphType = esriDataGraphTypeEnum.esriDataGraphTypeLine;

       proper.GraphSubtype = esriDataGraphSubtypeEnum.esriDataGraphSubtypeLine2DSimple;

       proper.ShowXAxisLabels = true;

       proper.ShowLegend = false;

       datagraph.Reload();

       datagraph.Draw();

       datagraph.ExportToFile("c:\\victorcxj.jpg"); 

       需要注意的是，如果是在b/s上做剖面图开发，上面的对象都不能用new 而是用serverContext来创建， 但我在开发中遇到一个奇怪的问题就是datagraph导不出来图片，我后来把DataGraph用new来创建就可以了，有时候AO的东西真是奇怪到你无法解释。。。。