// Calculates a geometric difference between features and user defined geometry
private async void DifferenceButton_Click(object sender, RoutedEventArgs e)
{
try
{
_differenceGraphics.Graphics.Clear();
// wait for user to draw difference polygon
var poly = await mapView.Editor.RequestShapeAsync(DrawShape.Polygon);
// Adjust user polygon for backward digitization
poly = GeometryEngine.Simplify(poly);
// get intersecting features from the feature layer
SpatialQueryFilter filter = new SpatialQueryFilter();
filter.Geometry = GeometryEngine.Project(poly, _statesLayer.FeatureTable.SpatialReference);
filter.SpatialRelationship = SpatialRelationship.Intersects;
filter.MaximumRows = 52;
var stateFeatures = await _statesLayer.FeatureTable.QueryAsync(filter);
// Calc difference between feature geometries and user polygon and add results to graphics layer
var states = stateFeatures.Select(feature => feature.Geometry);
var diffGraphics = states
.Select(state => ((bool)useSymmetricDifference.IsChecked)
? GeometryEngine.SymmetricDifference(state, poly)
: GeometryEngine.Difference(state, poly))
.Select(geo => new Graphic(geo, _fillSymbol));
_differenceGraphics.Graphics.AddRange(diffGraphics);
}
catch (Exception ex)
{
var _ = new MessageDialog("Difference Error: " + ex.Message, "Sample Error").ShowAsync();
}
}
// Handle selection events in the spatial operations picker.
private void OperationModel_ValueChanged(object sender, EventArgs e)
{
// Get the data model that contains the spatial operation choices.
PickerDataModel operationsModel = (PickerDataModel)_operationPicker.Model;
// If an operation hasn't been selected, return.
if (operationsModel.SelectedItem == "")
{
return;
}
// Remove any currently displayed result.
_polygonsOverlay.Graphics.Remove(_resultGraphic);
// Polygon geometry from the input graphics.
Geometry polygonOne = _graphicOne.Geometry;
Geometry polygonTwo = _graphicTwo.Geometry;
// Result polygon for spatial operations.
Geometry resultPolygon = null;
// Run the selected spatial operation on the polygon graphics and get the result geometry.
switch (operationsModel.SelectedItem)
{
case "Union":
resultPolygon = GeometryEngine.Union(polygonOne, polygonTwo);
break;
case "Difference":
resultPolygon = GeometryEngine.Difference(polygonOne, polygonTwo);
break;
case "Symmetric difference":
resultPolygon = GeometryEngine.SymmetricDifference(polygonOne, polygonTwo);
break;
case "Intersection":
resultPolygon = GeometryEngine.Intersection(polygonOne, polygonTwo);
break;
}
// Create a black outline symbol to use for the result polygon.
SimpleLineSymbol outlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Color.Black, 1);
// Create a solid red fill symbol for the result polygon graphic.
SimpleFillSymbol resultSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, Color.Red, outlineSymbol);
// Create the result polygon graphic and add it to the graphics overlay.
_resultGraphic = new Graphic(resultPolygon, resultSymbol);
_polygonsOverlay.Graphics.Add(_resultGraphic);
}
private void OperationsPicker_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e)
{
// If an operation hasn't been selected, return.
if (_operationPicker.SelectedItem.ToString() == "")
{
return;
}
// Remove any currently displayed result.
_polygonsOverlay.Graphics.Remove(_resultGraphic);
// Polygon geometry from the input graphics.
Geometry polygonOne = _graphicOne.Geometry;
Geometry polygonTwo = _graphicTwo.Geometry;
// Result polygon for spatial operations.
Geometry resultPolygon = null;
// Run the selected spatial operation on the polygon graphics and get the result geometry.
string selectedOperation = _operationPicker.SelectedItem.ToString();
switch (selectedOperation)
{
case "Union":
resultPolygon = GeometryEngine.Union(polygonOne, polygonTwo);
break;
case "Difference":
resultPolygon = GeometryEngine.Difference(polygonOne, polygonTwo);
break;
case "Symmetric difference":
resultPolygon = GeometryEngine.SymmetricDifference(polygonOne, polygonTwo);
break;
case "Intersection":
resultPolygon = GeometryEngine.Intersection(polygonOne, polygonTwo);
break;
}
// Create a black outline symbol to use for the result polygon.
SimpleLineSymbol outlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Color.Black, 1);
// Create a solid red fill symbol for the result polygon graphic.
SimpleFillSymbol resultSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, Color.Red, outlineSymbol);
// Create the result polygon graphic and add it to the graphics overlay.
_resultGraphic = new Graphic(resultPolygon, resultSymbol);
_polygonsOverlay.Graphics.Add(_resultGraphic);
}
// Handle the spatial operation selection by performing the operation and showing the result polygon.
private void SpatialOperationComboBox_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
// If an operation hasn't been selected, return.
if (SpatialOperationComboBox.SelectedItem == null)
{
return;
}
// Remove any currently displayed result.
_polygonsOverlay.Graphics.Remove(_resultGraphic);
// Polygon geometry from the input graphics.
Geometry polygonOne = _graphicOne.Geometry;
Geometry polygonTwo = _graphicTwo.Geometry;
// Result polygon for spatial operations.
Geometry resultPolygon = null;
// Run the selected spatial operation on the polygon graphics and get the result geometry.
string operation = (string)SpatialOperationComboBox.SelectedItem;
switch (operation)
{
case "Union":
resultPolygon = GeometryEngine.Union(polygonOne, polygonTwo);
break;
case "Difference":
resultPolygon = GeometryEngine.Difference(polygonOne, polygonTwo);
break;
case "Symmetric difference":
resultPolygon = GeometryEngine.SymmetricDifference(polygonOne, polygonTwo);
break;
case "Intersection":
resultPolygon = GeometryEngine.Intersection(polygonOne, polygonTwo);
break;
}
// Create a black outline symbol to use for the result polygon.
SimpleLineSymbol outlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, System.Drawing.Color.Black, 1);
// Create a solid red fill symbol for the result polygon graphic.
SimpleFillSymbol resultSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, System.Drawing.Color.Red, outlineSymbol);
// Create the result polygon graphic and add it to the graphics overlay.
_resultGraphic = new Graphic(resultPolygon, resultSymbol);
_polygonsOverlay.Graphics.Add(_resultGraphic);
}
void _operationChoiceButton_ValueChanged(object sender, EventArgs e)
{
// Remove any currently displayed result.
_polygonsOverlay.Graphics.Remove(_resultGraphic);
// Polygon geometry from the input graphics.
Geometry polygonOne = _graphicOne.Geometry;
Geometry polygonTwo = _graphicTwo.Geometry;
// Result polygon for spatial operations.
Geometry resultPolygon = null;
// Run the selected spatial operation on the polygon graphics and get the result geometry.
switch (_operationChoiceButton.SelectedSegment)
{
case 0:
resultPolygon = GeometryEngine.Difference(polygonOne, polygonTwo);
break;
case 1:
resultPolygon = GeometryEngine.Intersection(polygonOne, polygonTwo);
break;
case 2:
resultPolygon = GeometryEngine.SymmetricDifference(polygonOne, polygonTwo);
break;
case 3:
resultPolygon = GeometryEngine.Union(polygonOne, polygonTwo);
break;
}
// Create a black outline symbol to use for the result polygon.
SimpleLineSymbol outlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Color.Black, 1);
// Create a solid red fill symbol for the result polygon graphic.
SimpleFillSymbol resultSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, Color.Red, outlineSymbol);
// Create the result polygon graphic and add it to the graphics overlay.
_resultGraphic = new Graphic(resultPolygon, resultSymbol);
_polygonsOverlay.Graphics.Add(_resultGraphic);
}