private async void GetFeaturesFromQuery()
{
// Create a service feature table to get features from.
ServiceFeatureTable featTable = new ServiceFeatureTable(new Uri(FeatureLayerUrl));
// Create a query to get all features in the table.
QueryParameters queryParams = new QueryParameters
{
WhereClause = "1=1"
};
// Query the table to get all features.
FeatureQueryResult featureResult = await featTable.QueryFeaturesAsync(queryParams);
// Create a new feature collection table from the result features.
FeatureCollectionTable collectTable = new FeatureCollectionTable(featureResult);
// Create a feature collection and add the table.
FeatureCollection featCollection = new FeatureCollection();
featCollection.Tables.Add(collectTable);
// Create a layer to display the feature collection, add it to the map's operational layers.
FeatureCollectionLayer featureCollectionLayer = new FeatureCollectionLayer(featCollection);
_myMapView.Map.OperationalLayers.Add(featureCollectionLayer);
// Zoom to the extent of the feature collection layer.
await featureCollectionLayer.LoadAsync();
await _myMapView.SetViewpointGeometryAsync(featureCollectionLayer.FullExtent, 50);
}
private async void SaveFeatureCollectionFromQuery()
{
Debug.WriteLine("Creating feature collection from the service...");
// Create a service feature table to get features from
ServiceFeatureTable featTable = new ServiceFeatureTable(new Uri(FeatureLayerUrl));
// Create a query to get all features in the table
QueryParameters queryParams = new QueryParameters();
queryParams.WhereClause = "1=1";
// Query the table to get all features
FeatureQueryResult featureResult = await featTable.QueryFeaturesAsync(queryParams);
// Create a new feature collection table from the result features
FeatureCollectionTable collectTable = new FeatureCollectionTable(featureResult);
// Create a feature collection and add the table
FeatureCollection featCollection = new FeatureCollection();
featCollection.Tables.Add(collectTable);
var tokenServiceUri = new Uri("https://www.arcgis.com/sharing/rest"); // url for generating token
AuthenticationManager authManager = AuthenticationManager.Current;
var cred = await authManager.GenerateCredentialAsync(tokenServiceUri, "*******", "*******");
// Open a portal item containing a feature collection
ArcGISPortal portal = await ArcGISPortal.CreateAsync(tokenServiceUri, cred);
List <string> str = new List <string>();
str.Add("Save Feature collection");
FeatureCollectionLayer featCollectionTable = new FeatureCollectionLayer(featCollection);
await featCollectionTable.LoadAsync();
MyMapView.Map.OperationalLayers.Add(featCollectionTable);
Debug.WriteLine("Create a feature layer named, Feature Collection to Portal, and saving to portal...");
try
{
await featCollection.SaveAsAsync(portal, null, "Feature Collection to Portal", "FeatureCollection", str);
MessageBox.Show("Feature Collection saved to portal");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
private async void CreateNewFeatureCollection()
{
// Create the schema for a points table (one text field to contain a name attribute)
List <Field> pointFields = new List <Field>();
Field placeField = new Field(FieldType.Text, "Place", "Place Name", 50);
pointFields.Add(placeField);
// Create the schema for a lines table (one text field to contain a name attribute)
List <Field> lineFields = new List <Field>();
Field boundaryField = new Field(FieldType.Text, "Boundary", "Boundary Name", 50);
lineFields.Add(boundaryField);
// Create the schema for a polygon table (one text field to contain a name attribute)
List <Field> polyFields = new List <Field>();
Field areaField = new Field(FieldType.Text, "AreaName", "Area Name", 50);
polyFields.Add(areaField);
// Instantiate FeatureCollectionTables with schema and geometry type
FeatureCollectionTable pointsTable = new FeatureCollectionTable(pointFields, GeometryType.Point, SpatialReferences.Wgs84);
FeatureCollectionTable linesTable = new FeatureCollectionTable(lineFields, GeometryType.Polyline, SpatialReferences.Wgs84);
FeatureCollectionTable polysTable = new FeatureCollectionTable(polyFields, GeometryType.Polygon, SpatialReferences.Wgs84);
// Set rendering for each table
pointsTable.Renderer = CreateRenderer(GeometryType.Point);
linesTable.Renderer = CreateRenderer(GeometryType.Polyline);
polysTable.Renderer = CreateRenderer(GeometryType.Polygon);
// Create a new point feature, provide geometry and attribute values
Feature pointFeature = pointsTable.CreateFeature();
pointFeature.SetAttributeValue(placeField, "Current location");
MapPoint point1 = new MapPoint(-79.497238, 8.849289, SpatialReferences.Wgs84);
pointFeature.Geometry = point1;
// Create a new line feature, provide geometry and attribute values
Feature lineFeature = linesTable.CreateFeature();
lineFeature.SetAttributeValue(boundaryField, "AManAPlanACanalPanama");
MapPoint point2 = new MapPoint(-80.035568, 9.432302, SpatialReferences.Wgs84);
Polyline line = new Polyline(new MapPoint[] { point1, point2 });
lineFeature.Geometry = line;
// Create a new polygon feature, provide geometry and attribute values
Feature polyFeature = polysTable.CreateFeature();
polyFeature.SetAttributeValue(areaField, "Restricted area");
MapPoint point3 = new MapPoint(-79.337936, 8.638903, SpatialReferences.Wgs84);
MapPoint point4 = new MapPoint(-79.11409, 8.895422, SpatialReferences.Wgs84);
Polygon poly = new Polygon(new MapPoint[] { point1, point3, point4 });
polyFeature.Geometry = poly;
try
{
// Add the new features to the appropriate feature collection table
await pointsTable.AddFeatureAsync(pointFeature);
await linesTable.AddFeatureAsync(lineFeature);
await polysTable.AddFeatureAsync(polyFeature);
// Create a feature collection and add the feature collection tables
FeatureCollection featuresCollection = new FeatureCollection();
featuresCollection.Tables.Add(pointsTable);
featuresCollection.Tables.Add(linesTable);
featuresCollection.Tables.Add(polysTable);
// Create a FeatureCollectionLayer
FeatureCollectionLayer collectionLayer = new FeatureCollectionLayer(featuresCollection);
// When the layer loads, zoom the map centered on the feature collection
await collectionLayer.LoadAsync();
await MyMapView.SetViewpointCenterAsync(collectionLayer.FullExtent.GetCenter(), 1000000);
// Add the layer to the Map's Operational Layers collection
MyMapView.Map.OperationalLayers.Add(collectionLayer);
}
catch (Exception e)
{
await Application.Current.MainPage.DisplayAlert("Error", e.ToString(), "OK");
}
}
private async void CreateFeatureCollectionLayerFromNYTimesArticles()
{
// Read the NY Times data from the text file and get back a list of each article.
// The format of each record/article will look like:
// [Article summary]~[Article abstract]~[Country name]~[Url to the NY times article]~[Url to an image about the NY times article]~[Date of NY Times news article]
// Ex:
// Netanyahu not happy with Cohen~A spokesman for Prime Minister Benjamin Netanyahu disagrees with Roger Cohen’s “pessimism.”~Israel~https://www.nytimes.com/2018/01/02/opinion/israel-future.html~https://www.nytimes.com/images/2017/12/29/opinion/29cohenWeb/29cohenWeb-thumbLarge.jpg~20180102
List <string> myNYTimesArticles = ReadTextFile3(_NEWSFILE);
// Get the collection of all the layers in the map.
var myMapAllLayers = MyMapView.Map.AllLayers;
// Create a place holder for the world countries feature layer.
FeatureLayer myFeatureLayer = null;
// Loop through all of the layers.
foreach (var myLayer in myMapAllLayers)
{
// Get the Id of the layer.
string myLayerName = myLayer.Id;
// If the layer id matches world countries set that to the feature layer.
if (myLayerName == "WorldCountries")
{
myFeatureLayer = (FeatureLayer)myLayer;
}
}
// Get the feature table from the world countries shape file feature layer.
FeatureTable myFeatureTable = myFeatureLayer.FeatureTable;
// Create a new query parameters.
QueryParameters myQueryParameters = new QueryParameters();
// Define the where clause for the query parameters. It will select all the records in the world countries shape file feature table.
myQueryParameters.WhereClause = "1 = 1";
// Execute the feature query and get the results back. It will select all the records in the world countries shape file feature table.
FeatureQueryResult myFeatureQueryResult = await myFeatureTable.QueryFeaturesAsync(myQueryParameters);
// Create the schema for the polygon feature collection table.
List <Field> myFeatureCollectionAttributeFields = new List <Field>();
// Create a field for the feature collection layer. It will contain a text field called area name that is the county name.
Field myAreaNameField = new Field(FieldType.Text, "AreaName", "Area Name", 50);
// Add the country name field to the list of fields that will be added to the feature collection table.
myFeatureCollectionAttributeFields.Add(myAreaNameField);
// Create the feature collection table based on the list of attribute fields, a polygons feature type
FeatureCollectionTable myFeatureCollectionTable = new FeatureCollectionTable(myFeatureCollectionAttributeFields, GeometryType.Polygon, SpatialReferences.Wgs84);
// Create the outline symbol for the country fill symbol.
SimpleLineSymbol mySimpleLineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Color.DarkBlue, 2);
// Create the fill symbol for the country. Solid yellow, with dark blue outline.
SimpleFillSymbol mySimpleFillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, Color.Yellow, mySimpleLineSymbol);
// Set the renderer of the feature collection table to be the simple fill symbol.
myFeatureCollectionTable.Renderer = new SimpleRenderer(mySimpleFillSymbol);
// Loop through each feature in the returned feature query results of the world countries shape file
foreach (Feature myFeature in myFeatureQueryResult)
{
// Get the geometry (aka shape) for one feature.
Geometry myGeometry = myFeature.Geometry;
// Get the value (aka. the text for the record of a specific field).
var myValue = (string)myFeature.Attributes["NAME"];
// Loop through each NY Times article.
foreach (string oneNYTimesArticle in myNYTimesArticles)
{
// Remove an embedded double quotes that may be in or surrounding the country name in the NY Times data base.
char[] charsToTrim = { '"' };
string country = oneNYTimesArticle.Split('~')[2].Trim(charsToTrim);
// Find a match from the shape file country feature and the NY Times country name in the article.
if ((string)myValue == country)
{
// Create a new polygon feature, provide geometry and attribute values.
Feature polyFeature = myFeatureCollectionTable.CreateFeature();
polyFeature.SetAttributeValue(myAreaNameField, country);
polyFeature.Geometry = myGeometry;
// Add the new features to the appropriate feature collection table.
await myFeatureCollectionTable.AddFeatureAsync(polyFeature);
// Once we have found a matching country in the subset news article file that matches a shape file record
// there is no need to find another one since we have just created a record in the FeatureCollectionTable.
break;
}
}
}
// Create a feature collection and add the feature collection tables
FeatureCollection myFeatureCollection = new FeatureCollection();
myFeatureCollection.Tables.Add(myFeatureCollectionTable);
// Create a FeatureCollectionLayer
FeatureCollectionLayer myFeatureCollectionLayer = new FeatureCollectionLayer(myFeatureCollection);
myFeatureCollectionLayer.Id = "Joined"; // might not be needed
myFeatureCollectionLayer.Name = "JoinedFCL";
// When the layer loads, zoom the map centered on the feature collection
await myFeatureCollectionLayer.LoadAsync();
// Add the layer to the Map's Operational Layers collection
MyMapView.Map.OperationalLayers.Add(myFeatureCollectionLayer);
}