ArcGIS Pro SDK （九）几何 14 检索与导入、导出

文章目录

ArcGIS Pro SDK （九）几何 14 检索与导入、导出
- 1 从地理数据库检索几何
- 2 将几何图形导入和导出为已知文本
- 3 将几何图形导入和导出到众所周知的二进制
- 4 将几何导入和导出到 EsriShape
- 5 将几何图形导入和导出为 JSON
- 6 将几何图形导入和导出为 XML

环境：Visual Studio 2022 + .NET6 + ArcGIS Pro SDK 3.0

1 从地理数据库检索几何

// 方法需要在MCT上运行
ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>{try{// 打开一个gdbusing (ArcGIS.Core.Data.Geodatabase gdb = new ArcGIS.Core.Data.Geodatabase(new FileGeodatabaseConnectionPath(new Uri(@"c:\Temp\MyDatabase.gdb")))){// 打开一个要素类using (ArcGIS.Core.Data.FeatureClass featureClass = gdb.OpenDataset<ArcGIS.Core.Data.FeatureClass>("Polygon")){ArcGIS.Core.Data.QueryFilter filter = new ArcGIS.Core.Data.QueryFilter(){WhereClause = "OBJECTID = 6"};// 获取行using (ArcGIS.Core.Data.RowCursor rowCursor = featureClass.Search(filter, false)){while (rowCursor.MoveNext()){using (var row = rowCursor.Current){long oid = row.GetObjectID();// 从行中获取形状ArcGIS.Core.Data.Feature feature = row as ArcGIS.Core.Data.Feature;Polygon polygon = feature.GetShape() as Polygon;// 在这里做一些处理}}}}}}catch (Exception ex){// 错误 - 适当处理}});

2 将几何图形导入和导出为已知文本

// 创建一个带有 z 和 m 的点
MapPoint point = MapPointBuilderEx.CreateMapPoint(100, 200, 300, 400, SpatialReferences.WebMercator);// 设置标志
WktExportFlags wktExportFlags = WktExportFlags.WktExportDefaults;
WktImportFlags wktImportFlags = WktImportFlags.WktImportDefaults;// 导出和导入
string wktString = GeometryEngine.Instance.ExportToWKT(wktExportFlags, point);
MapPoint importPoint = GeometryEngine.Instance.ImportFromWKT(wktImportFlags, wktString, SpatialReferences.WebMercator) as MapPoint;double x = importPoint.X;       // x = 100
double y = importPoint.Y;       // y = 200
bool hasZ = importPoint.HasZ;   // hasZ = true
double z = importPoint.Z;       // z = 300
bool hasM = importPoint.HasM;   // hasM = true
double m = importPoint.M;       // m = 400// 不带 z 的导出
WktExportFlags exportFlagsNoZ = WktExportFlags.WktExportStripZs;
wktString = GeometryEngine.Instance.ExportToWKT(exportFlagsNoZ, point);
importPoint = GeometryEngine.Instance.ImportFromWKT(wktImportFlags, wktString, SpatialReferences.WebMercator) as MapPoint;x = importPoint.X;        // x = 100
y = importPoint.Y;        // y = 200
hasZ = importPoint.HasZ;  // hasZ = false
z = importPoint.Z;        // z = 0
hasM = importPoint.HasM;  // hasM = true
m = importPoint.M;        // m = 400// 不带 m 的导出
WktExportFlags exportFlagsNoM = WktExportFlags.WktExportStripMs;
wktString = GeometryEngine.Instance.ExportToWKT(exportFlagsNoM, point);
importPoint = GeometryEngine.Instance.ImportFromWKT(wktImportFlags, wktString, SpatialReferences.WebMercator) as MapPoint;x = importPoint.X;        // x = 100
y = importPoint.Y;        // y = 200
hasZ = importPoint.HasZ;  // hasZ = true
z = importPoint.Z;        // z = 300
hasM = importPoint.HasM;  // hasM = false
m = importPoint.M;        // m = Nan// 不带 z 和 m 的导出
wktString = GeometryEngine.Instance.ExportToWKT(exportFlagsNoZ | exportFlagsNoM, point);
importPoint = GeometryEngine.Instance.ImportFromWKT(wktImportFlags, wktString, SpatialReferences.WebMercator) as MapPoint;x = importPoint.X;        // x = 100
y = importPoint.Y;        // y = 200
hasZ = importPoint.HasZ;  // hasZ = false
z = importPoint.Z;        // z = 0
hasM = importPoint.HasM;  // hasM = false
m = importPoint.M;        // m = Nan

3 将几何图形导入和导出到众所周知的二进制

// 创建一条折线
List<Coordinate2D> coords = new List<Coordinate2D>
{new Coordinate2D(0, 0),new Coordinate2D(0, 1),new Coordinate2D(1, 1),new Coordinate2D(1, 0)
};Polyline polyline = PolylineBuilderEx.CreatePolyline(coords, SpatialReferences.WGS84);WkbExportFlags wkbExportFlags = WkbExportFlags.WkbExportDefaults;
WkbImportFlags wkbImportFlags = WkbImportFlags.WkbImportDefaults;// 导出和导入
byte[] buffer = GeometryEngine.Instance.ExportToWKB(wkbExportFlags, polyline);
Geometry geometry = GeometryEngine.Instance.ImportFromWKB(wkbImportFlags, buffer, SpatialReferences.WGS84);
Polyline importPolyline = geometry as Polyline;// 或者，确定缓冲区的大小
int bufferSize = GeometryEngine.Instance.GetWKBSize(wkbExportFlags, polyline);
buffer = new byte[bufferSize];
// 导出
bufferSize = GeometryEngine.Instance.ExportToWKB(wkbExportFlags, polyline, ref buffer);
// 导入
importPolyline = GeometryEngine.Instance.ImportFromWKB(wkbImportFlags, buffer, SpatialReferences.WGS84) as Polyline;

4 将几何导入和导出到 EsriShape

// 创建一个包络线
List<MapPoint> coordsZM = new List<MapPoint>
{MapPointBuilderEx.CreateMapPoint(1001, 1002, 1003, 1004),MapPointBuilderEx.CreateMapPoint(2001, 2002, Double.NaN, 2004),MapPointBuilderEx.CreateMapPoint(3001, -3002, 3003, 3004),MapPointBuilderEx.CreateMapPoint(1001, -4002, 4003, 4004)
};Envelope envelope = EnvelopeBuilderEx.CreateEnvelope(coordsZM[0], coordsZM[2], SpatialReferences.WGS84);// 导出和导入
EsriShapeExportFlags exportFlags = EsriShapeExportFlags.EsriShapeExportDefaults;
EsriShapeImportFlags importFlags = EsriShapeImportFlags.EsriShapeImportDefaults;
byte[] buffer = GeometryEngine.Instance.ExportToEsriShape(exportFlags, envelope);
Polygon importedPolygon = GeometryEngine.Instance.ImportFromEsriShape(importFlags, buffer, envelope.SpatialReference) as Polygon;
Envelope importedEnvelope = importedPolygon.Extent;// 不带 z 和 m 的导出
buffer = GeometryEngine.Instance.ExportToEsriShape(EsriShapeExportFlags.EsriShapeExportStripZs | EsriShapeExportFlags.EsriShapeExportStripMs, envelope);
importedPolygon = GeometryEngine.Instance.ImportFromEsriShape(importFlags, buffer, SpatialReferences.WGS84) as Polygon;
importedEnvelope = importedPolygon.Extent;bool hasZ = importedEnvelope.HasZ;      // hasZ = false
bool hasM = importedEnvelope.HasM;      // hasM = false// 使用 shapeSize 导出
int bufferSize = GeometryEngine.Instance.GetEsriShapeSize(exportFlags, envelope);
buffer = new byte[bufferSize];bufferSize = GeometryEngine.Instance.ExportToEsriShape(exportFlags, envelope, ref buffer);
importedPolygon = GeometryEngine.Instance.ImportFromEsriShape(importFlags, buffer, envelope.SpatialReference) as Polygon;
importedEnvelope = importedPolygon.Extent;// 或使用 envelope 和 envelopeBuilderEx 类
buffer = envelope.ToEsriShape();
// buffer 表示一个多边形，因为没有包络线 Esri shape 缓冲区
// EnvelopeBuilderEx.FromEsriShape 将多边形 Esri shape 缓冲区转换为多边形的范围。
importedEnvelope = EnvelopeBuilderEx.FromEsriShape(buffer);

5 将几何图形导入和导出为 JSON

// MapPoint
string inputString = "{\"x\":1,\"y\":2,\"spatialReference\":{\"wkid\":4326,\"latestWkid\":4326}}";
Geometry geometry = GeometryEngine.Instance.ImportFromJson(JsonImportFlags.JsonImportDefaults, inputString);MapPoint importPoint = geometry as MapPoint;
// importPoint = 1, 2
// importPoint.SpatialReference.WKid = 4326// 使用 MapPointBuilderEx 的便捷方法
MapPoint importPoint2 = MapPointBuilderEx.FromJson(inputString);
// importPoint2 = 1, 2
// impointPoint2.SpatialReference.Wkid = 4326string outputString = GeometryEngine.Instance.ExportToJson(JsonExportFlags.JsonExportDefaults, importPoint);
// outputString =
//   "{\"x\":1,\"y\":2,\"spatialReference\":{\"wkid\":4326,\"latestWkid\":4326}}"string outputString2 = importPoint.ToJson();inputString = "{\"spatialReference\":{\"wkid\":4326},\"z\":3,\"m\":4,\"x\":1,\"y\":2}";
importPoint = GeometryEngine.Instance.ImportFromJson(JsonImportFlags.JsonImportDefaults, inputString) as MapPoint;
// importPoint.HasM = true
// importPoint.HasZ = true
// importPoint.X = 1
// importPoint.Y = 2
// importPoint.M = 4
// importPoint.Z = 3importPoint2 = MapPointBuilderEx.FromJson(inputString);// 导出到 JSON - 跳过空间参考
outputString = GeometryEngine.Instance.ExportToJson(JsonExportFlags.JsonExportSkipCRS, importPoint);
// outputString = "{\"x\":1,\"y\":2,\"z\":3,\"m\":4}"// 从 MapPoint 导出，跳过空间参考 - 同 GeometryEngine.Instance.ExportToJson w JsonExportFlags.JsonExportSkipCRS
outputString2 = importPoint.ToJson(true);//
// Multipoint
//
List<Coordinate2D> coords = new List<Coordinate2D>()
{new Coordinate2D(100, 200),new Coordinate2D(201, 300),new Coordinate2D(301, 400),new Coordinate2D(401, 500)
};Multipoint multipoint = MultipointBuilderEx.CreateMultipoint(coords, SpatialReferences.WebMercator);inputString = "{\"points\":[[100,200],[201,300],[301,400],[401,500]],\"spatialReference\":{\"wkid\":3857}}";
Multipoint importMultipoint = GeometryEngine.Instance.ImportFromJson(JsonImportFlags.JsonImportDefaults, inputString) as Multipoint;
// importMultipoint.IsEqual(multipoint) = trueReadOnlyPointCollection points = importMultipoint.Points;
// points.Count = 4
// points[0] = 100, 200
// points[1] = 201, 300
// points[2] = 301, 400
// points[3] = 401, 500// 使用 MultipointBuilderEx 的便捷方法
Multipoint importMultipoint2 = MultipointBuilderEx.FromJson(inputString);
// importMultipoint2.IsEqual(multipoint) = true// 导出到 JSON
outputString = GeometryEngine.Instance.ExportToJson(JsonExportFlags.JsonExportDefaults, multipoint);
// outputString = inputString// 或者直接使用 multipoint 对象
outputString2 = multipoint.ToJson();//
// Polyline
//
Polyline polyline = PolylineBuilderEx.CreatePolyline(coords, SpatialReferences.WebMercator);// 导出时不带空间参考
outputString = GeometryEngine.Instance.ExportToJson(JsonExportFlags.JsonExportSkipCRS, polyline);
// 导入
geometry = GeometryEngine.Instance.ImportFromJson(JsonImportFlags.JsonImportDefaults, outputString);
Polyline importPolyline = geometry as Polyline;
// importPolyline.SpatialReference = nullpoints = importPolyline.Points;
// points.Count = 4
// points[0] = 100, 200
// points[1] = 201, 300
// points[2] = 301, 400
// points[3] = 401, 500// 使用 PolylineBuilderEx 的便捷方法 
Polyline importPolyline2 = PolylineBuilderEx.FromJson(outputString);
// importPolyline2 = importPolylineoutputString2 = importPolyline2.ToJson();
// outputString2 = outputString//
// Polygon
//
Polygon polygon = PolygonBuilderEx.CreatePolygon(coords, SpatialReferences.WebMercator);// 导出时不带空间参考
outputString = GeometryEngine.Instance.ExportToJson(JsonExportFlags.JsonExportSkipCRS, polygon);
// 导入
geometry = GeometryEngine.Instance.ImportFromJson(JsonImportFlags.JsonImportDefaults, outputString);Polygon importPolygon = geometry as Polygon;
// importPolygon.SpatialReference = null
points = importPolygon.Points;
// points.Count = 5// 使用 PolygonBuilderEx 的便捷方法
Polygon importPolygon2 = PolygonBuilderEx.FromJson(outputString);
// importPolygon2 = importPolygon// 从 polygon 导出
outputString2 = importPolygon2.ToJson(true);// 空的 polygon
polygon = PolygonBuilderEx.CreatePolygon(SpatialReferences.WebMercator);
outputString = GeometryEngine.Instance.ExportToJson(JsonExportFlags.JsonExportDefaults, polygon);
importPolygon = GeometryEngine.Instance.ImportFromJson(JsonImportFlags.JsonImportDefaults, outputString) as Polygon;// importPolygon.IsEmpty = true
// importPolygon.SpatialReference.Wkid = 3857

6 将几何图形导入和导出为 XML

MapPoint minPoint = MapPointBuilderEx.CreateMapPoint(1, 1, 1, 1, 3);
MapPoint maxPoint = MapPointBuilderEx.CreateMapPoint(5, 5, 5);// 
//  MapPoint
// 
string xml = minPoint.ToXml();
MapPoint minPointImport = MapPointBuilderEx.FromXml(xml);
// minPointImport = minPoint//
// Envelope
//
Envelope envelopeWithID = EnvelopeBuilderEx.CreateEnvelope(minPoint, maxPoint);// 包络线没有 ID
// envelopeWithID.HasID = false
// envelopeWithID.HasM = true
// envelopeWithID.HasZ = truexml = envelopeWithID.ToXml();
Envelope envelopeImport = EnvelopeBuilderEx.FromXml(xml);//
// Multipoint
//
List<MapPoint> list = new List<MapPoint>();
list.Add(minPoint);
list.Add(maxPoint);Multipoint multiPoint = MultipointBuilderEx.CreateMultipoint(list);xml = multiPoint.ToXml();
Multipoint multipointImport = MultipointBuilderEx.FromXml(xml);
// multipointImport.PointCount == 2
// multipointImport.HasID = true
// multipointImport.HasM = true
// multipointImport.HasZ = true