/// <summary>
/// 判断数据是否是有效数据
/// </summary>
/// <returns></returns>
public bool IsValidDataSource()
{
_ogrLayer.ResetReading();
int featureCount = _ogrLayer.GetFeatureCount(1);
if (featureCount <= 0)
{
return(false);
}
Feature pFeature = _ogrLayer.GetNextFeature();
if (pFeature == null)
{
return(false);
}
Geometry pGeom = pFeature.GetGeometryRef();
if (pGeom == null)
{
return(false);
}
if (pGeom.GetGeometryType() == wkbGeometryType.wkbNone || pGeom.GetGeometryType() == wkbGeometryType.wkbUnknown)
{
return(false);
}
return(true);
}
/// <summary>
/// Returns geometry Object IDs whose bounding box intersects 'bbox'
/// </summary>
/// <param name="bbox"></param>
/// <returns></returns>
public Collection <uint> GetObjectIDsInView(SharpMap.Geometries.BoundingBox bbox)
{
_OgrLayer.SetSpatialFilterRect(bbox.Min.X, bbox.Min.Y, bbox.Max.X, bbox.Max.Y);
OSGeo.OGR.Feature _OgrFeature = null;
_OgrLayer.ResetReading();
Collection <uint> _ObjectIDs = new Collection <uint>();
while ((_OgrFeature = _OgrLayer.GetNextFeature()) != null)
{
_ObjectIDs.Add((uint)_OgrFeature.GetFID());
_OgrFeature.Dispose();
}
return(_ObjectIDs);
}
/// <summary>
/// Returns geometry Object IDs whose bounding box intersects 'bbox'
/// </summary>
/// <param name="bbox"></param>
/// <returns></returns>
public Collection <uint> GetObjectIDsInView(IEnvelope bbox)
{
_OgrLayer.SetSpatialFilterRect(bbox.MinX, bbox.MinY, bbox.MaxX, bbox.MaxY);
OSGeo.OGR.Feature _OgrFeature = null;
_OgrLayer.ResetReading();
Collection <uint> _ObjectIDs = new Collection <uint>();
while ((_OgrFeature = _OgrLayer.GetNextFeature()) != null)
{
_ObjectIDs.Add((uint)_OgrFeature.GetFID());
_OgrFeature.Dispose();
}
return(_ObjectIDs);
}
public static string ToGeoJson(string shpPath)
{
OSGeo.OGR.Ogr.RegisterAll();
Driver drv = Ogr.GetDriverByName("ESRI Shapefile");
using (var ds = drv.Open(shpPath, 0))
{
OSGeo.OGR.Layer layer = ds.GetLayerByIndex(0);
OSGeo.OGR.Feature f;
layer.ResetReading();
System.Text.StringBuilder sb = new System.Text.StringBuilder();
while ((f = layer.GetNextFeature()) != null)
{
var geom = f.GetGeometryRef();
if (geom != null)
{
var geometryJson = geom.ExportToJson(null);
sb.AppendLine(geometryJson);
}
}
return(sb.ToString());
}
}
public static void ConvertSHPtoGJSON(string shapefilePath, out StringBuilder gJSON)
{
string shpPath = shapefilePath;
Ogr.RegisterAll();
OSGeo.OGR.Driver drv = Ogr.GetDriverByName("ESRI Shapefile");
var ds = drv.Open(shpPath, 0);
/*
* Driver geoJSONDriver = Ogr.GetDriverByName("GeoJSON");
*
* string geojsonfilepath = @"c:\temp\us_counties_test.json";
*
* if (System.IO.File.Exists(geojsonfilepath))
* System.IO.File.Delete(geojsonfilepath);
*
* geoJSONDriver.CreateDataSource(@"c:\temp\us_counties_test.json", null);
*/
OSGeo.OGR.Layer layer = ds.GetLayerByIndex(0);
OSGeo.OGR.Feature f;
layer.ResetReading();
System.Text.StringBuilder sb = new System.Text.StringBuilder();
var options = new[]
{
"-f", "GeoJSON",
"-lco", "RFC7946=YES"
};
while ((f = layer.GetNextFeature()) != null)
{
var geom = f.GetGeometryRef();
if (geom != null)
{
var geometryJson = geom.ExportToJson(options);
sb.AppendLine(geometryJson);
}
}
gJSON = sb;
}
