/// <summary>
/// Calculates the data statistics for a geodatabase table.
/// </summary>
/// <param name="table">The geodatabase table which statistics should be gathered.</param>
/// <param name="field">The field which statistics should be gathered.</param>
/// <returns>The calculated data statistics.</returns>
internal async Task<DataStatisticsResult> CalculateStatistics(FeatureTable table, FieldInfo field)
{
var result = new DataStatisticsResult { TableName = table.Name, AttributeName = field.Alias };
result.Count = table.RowCount;
var filter = new QueryFilter { WhereClause = @"1=1" };
var features = await table.QueryAsync(filter);
var uniqueValues = new HashSet<object>();
foreach (var feature in features)
{
var attributes = feature.Attributes;
if (attributes.ContainsKey(field.Name))
{
var value = attributes[field.Name];
if (!uniqueValues.Contains(value))
{
uniqueValues.Add(value);
}
}
}
result.UniqueValueCount = uniqueValues.Count;
return result;
}
// Summary:
// Load features in a FeatureTable into a GraphicsLayer
//
async Task <IS3GraphicsLayer> featureTable2GraphicsLayer(FeatureTable table,
int start = 0, int maxFeatures = 0, bool isShp = false)
{
if (table == null)
{
return(null);
}
if (_srEMap == null)
{
// The spatial reference in the first table is used as the project spatial reference.
// All features on other layers will be projected to the spatial reference.
_srEMap = table.SpatialReference;
_map.SpatialReference = table.SpatialReference;
}
//// We cannot use the feature layer class because it typically
//// has a different SpatialReferece object (coordinate system)
//// other than the tiled layer (WKID = 3857 or 102100),
//// and there is no easy way to reproject feature layer
//// to another coordinate system.
//// We can only use the feature layer when there is no tiled layer defined,
//// which is not a usual case.
//FeatureLayer fLayer = new FeatureLayer(table);
//fLayer.ID = table.Name;
//fLayer.DisplayName = table.Name;
//_map.Layers.Add(fLayer);
QueryFilter qf = new QueryFilter();
qf.WhereClause = "1=1";
IEnumerable <Feature> features = await table.QueryAsync(qf);
IS3GraphicCollection graphics = new IS3GraphicCollection();
int index = 0, count = 0;
foreach (Feature f in features)
{
// jump to start position
if (index++ < start)
{
continue;
}
// Note:
// In ArcGIS Runtime SDK: User-defined coordinate system
// is not allowed when using ShapefileTable.OpenAsync().
// Workaround:
// (1) Do not assign user-defined CS in shape file;
// (2) Assign CS dynamically here to _srEMap.
//
Geometry geometry = f.Geometry;
if (isShp == true)
{
geometry = ArcGISMappingUtility.ChangeSpatailReference(geometry, _srEMap);
if (geometry == null)
{
continue;
}
}
if (_srEMap != null && isShp == false && geometry.SpatialReference != _srEMap)
{
geometry = GeometryEngine.Project(geometry, _srEMap);
}
// import the attributes
IS3Graphic g = new IS3Graphic(geometry);
foreach (KeyValuePair <string, object> item in f.Attributes.AsEnumerable())
{
g.Attributes.Add(item);
}
graphics.Add(g);
// Load max featuers
if (maxFeatures != 0 && count++ == maxFeatures)
{
break;
}
}
IS3GraphicsLayer gLayer = new IS3GraphicsLayer();
gLayer.DisplayName = table.Name;
gLayer.GraphicsSource = graphics;
gLayer.geometryType = (Core.Model.GeometryType)(int) table.GeometryType;
return(gLayer);
}
// Summary:
// Load features in a FeatureTable into a GraphicsLayer
//
async Task<IS3GraphicsLayer> featureTable2GraphicsLayer(FeatureTable table,
int start = 0, int maxFeatures = 0, bool isShp = false)
{
if (table == null)
return null;
if (_srEMap == null)
{
// The spatial reference in the first table is used as the project spatial reference.
// All features on other layers will be projected to the spatial reference.
_srEMap = table.SpatialReference;
_map.SpatialReference = table.SpatialReference;
}
//// We cannot use the feature layer class because it typically
//// has a different SpatialReferece object (coordinate system)
//// other than the tiled layer (WKID = 3857 or 102100),
//// and there is no easy way to reproject feature layer
//// to another coordinate system.
//// We can only use the feature layer when there is no tiled layer defined,
//// which is not a usual case.
//FeatureLayer fLayer = new FeatureLayer(table);
//fLayer.ID = table.Name;
//fLayer.DisplayName = table.Name;
//_map.Layers.Add(fLayer);
QueryFilter qf = new QueryFilter();
qf.WhereClause = "1=1";
IEnumerable<Feature> features = await table.QueryAsync(qf);
IS3GraphicCollection graphics = new IS3GraphicCollection();
int index = 0, count = 0;
foreach (Feature f in features)
{
// jump to start position
if (index++ < start)
continue;
// Note:
// In ArcGIS Runtime SDK: User-defined coordinate system
// is not allowed when using ShapefileTable.OpenAsync().
// Workaround:
// (1) Do not assign user-defined CS in shape file;
// (2) Assign CS dynamically here to _srEMap.
//
Geometry geometry = f.Geometry;
if (isShp == true)
{
geometry = ArcGISMappingUtility.ChangeSpatailReference(geometry, _srEMap);
if (geometry == null)
continue;
}
if (_srEMap != null && isShp == false && geometry.SpatialReference != _srEMap)
geometry = GeometryEngine.Project(geometry, _srEMap);
// import the attributes
IS3Graphic g = new IS3Graphic(geometry);
foreach (KeyValuePair<string, object> item in f.Attributes.AsEnumerable())
g.Attributes.Add(item);
graphics.Add(g);
// Load max featuers
if (maxFeatures != 0 && count++ == maxFeatures)
break;
}
IS3GraphicsLayer gLayer = new IS3GraphicsLayer();
gLayer.DisplayName = table.Name;
gLayer.GraphicsSource = graphics;
gLayer.geometryType = (IS3.Core.Geometry.GeometryType)(int)table.GeometryType;
return gLayer;
}
