本文用于记录一些使用频率较高但归类繁杂，非系统性的一些代码。

主要方便自己使用和查阅，随时更新。

---

1、从GDB数据库中打开【FeatureDataset\FeatureClass\Table】

using Geodatabase gdb = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri(gdbPath)));
FeatureDataset featureDataset = gdb.OpenDataset<FeatureDataset>(featureDatasetName);
FeatureClass featureClass = gdb.OpenDataset<FeatureClass>(featureClassName);
Table table = gdb.OpenDataset<Table>(tableName);

2、从GDB数据库中获取【FeatureDatasetDefinition\FeatureClassDefinition\TableDefinition】

// 扩展用法：GetDefinitions<>
FeatureDatasetDefinition featureDatasetDefinition = gdb.GetDefinition<FeatureDatasetDefinition>(featureDatasetName);
FeatureClassDefinition featureClassDefinition = gdb.GetDefinition<FeatureClassDefinition>(featureClassName);
TableDefinition tableDefinition = gdb.GetDefinition<TableDefinition>(tableName);

3、从【FeatureLayer\FeatureClass】中获取【Feature\Row】

using (RowCursor rowCursor = featureLayer.Search())
{while (rowCursor.MoveNext()){using Feature feature2 = rowCursor.Current as Feature;using Row row = rowCursor.Current;}
}

4、Feature转换为Geometry

Geometry geometry1 = feature.GetShape();

5、Geometry转换为Polygon

Polygon polygon1 = geometry as Polygon;

6、设置Feature的几何形状

feature.SetShape(geometry);

7、获取线、面要素的折点、首末点

ReadOnlyPointCollection mapPoints = polygon.Points;
ReadOnlyPointCollection mapPoints2 = polyline.Points;
MapPoint startPoint = mapPoints.First();
MapPoint endPoint = mapPoints.Last();

8、switch用法示例

string featureclass_type = esriGeometryType switch
{esriGeometryType.esriGeometryPoint => "Point",esriGeometryType.esriGeometryPolyline => "Polyline",esriGeometryType.esriGeometryPolygon => "Polygon",_ => "",
};

9、获取活动地图视图中选择框选定的要素【SelectiontSet】

SelectionSet selectedSet = MapView.Active.Map.GetSelection();

10、在MapTool中获取选择的要素【SelectiontSet】

SelectionSet selectedSet2 = MapView.Active.GetFeatures(geometry);

11、从【SelectionSet】中获取【Geometry】

var selectionList = selectedSet.ToDictionary();
Inspector inspector = new Inspector();
foreach (var selection in selectionList)
{MapMember mapMember = selection.Key;List<long> oids = selection.Value;foreach (var oid in oids){inspector.Load(mapMember, oid);Polygon polygon2 = inspector.Shape as Polygon;}
}

12、Geometry的属性

double polygonArea = polygon.Area;  // 面积
Envelope polygonExtent = polygon.Extent;   // 范围
GeometryType geometryType = geometry.GeometryType;  // 要素类型
SpatialReference spatialReference = geometry.SpatialReference;   // 坐标系
int pointCount = polyline.PointCount;    // 折点数