I'm attempting to load some road data from a shapefile, drawing them onscreen in different colours depending upon classification. Later I attempt to run a spacial query on the underlying data. I've attempted to knock up a working query using the examples in the API, however the code never returns any matching results.
The loading code is as follows:
protected void LoadRoads()
{
// Loads the shape files which render positions of network roads
// Load the 1-3 shape files, rebuilding indexes if not valid
String roadsShapefile = "C:\shapefiles\Roads.shp";
ShapeFileFeatureLayer.BuildIndexFile(roadsShapefile, BuildIndexMode.DoNotRebuild);
// Create a new value style which will draw line a single pixel line in the relevant colour between levels 1 and 10
ValueStyle roadNetworkValueStyle = new ValueStyle();
roadNetworkValueStyle.ColumnName = "ROAD_TYPE";
roadNetworkValueStyle.ValueItems.Add(new ValueItem("Motorway", new LineStyle(new GeoPen(GeoColor.FromArgb(255, 107, 178, 247), 1))));
roadNetworkValueStyle.ValueItems.Add(new ValueItem("Other", new LineStyle(new GeoPen(GeoColor.FromArgb(255, 132, 178, 140), 1))));
// Create a new value style which will draw line a double pixel line in the relevant colour between levels 11 and 20
ValueStyle roadNetworkValueStyle2 = new ValueStyle();
roadNetworkValueStyle2.ColumnName = "ROAD_TYPE";
roadNetworkValueStyle2.ValueItems.Add(new ValueItem("Motorway", new LineStyle(new GeoPen(GeoColor.FromArgb(255, 107, 178, 247), 2))));
roadNetworkValueStyle2.ValueItems.Add(new ValueItem("Other", new LineStyle(new GeoPen(GeoColor.FromArgb(255, 132, 178, 140), 3))));
// Create a feature layer to hold the shape file, then apply the value styles to the relevant levels
ShapeFileFeatureLayer shapeFileFeatureLayer = new ShapeFileFeatureLayer(roadsShapefile);
shapeFileFeatureLayer.ZoomLevelSet.ZoomLevel01.CustomStyles.Add(roadNetworkValueStyle);
shapeFileFeatureLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level10;
shapeFileFeatureLayer.ZoomLevelSet.ZoomLevel11.CustomStyles.Add(roadNetworkValueStyle2);
shapeFileFeatureLayer.ZoomLevelSet.ZoomLevel11.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
// Define a shape overlay for the road layer.
LayerOverlay shapeOverlay = new LayerOverlay("Roads", false, TileType.SingleTile);
shapeOverlay.Layers.Add("Roads", shapeFileFeatureLayer);
shapeOverlay.TransitionEffect = TransitionEffect.Stretching;
myAreasMap.CustomOverlays.Add(shapeOverlay);
}
And here is the code which attempts to run the query:
protected void QueryTest()
{
// Begin by drawing a rectangle over the map
InMemoryFeatureLayer rectangleLayer = new InMemoryFeatureLayer();
rectangleLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = new AreaStyle(new GeoSolidBrush(new GeoColor(50, 100, 100, 200)));
rectangleLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle.OutlinePen.Color = GeoColor.StandardColors.DarkBlue;
rectangleLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
BaseShape baseShape = BaseShape.CreateShapeFromWellKnownData("POLYGON((150000 100000, 150000 500000, 675000 500000, 675000 100000, 150000 100000))");
rectangleLayer.InternalFeatures.Add("Rectangle", new Feature(baseShape));
rectangleLayer.BuildIndex();
// Define a shape overlay, add the layer and place it on the map
LayerOverlay rectangleOverlay = new LayerOverlay("Rectangle", false, TileType.SingleTile);
rectangleOverlay.Layers.Add("Rectangle", rectangleLayer);
rectangleOverlay.TransitionEffect = TransitionEffect.Stretching;
myAreasMap.CustomOverlays.Add(rectangleOverlay);
InMemoryFeatureLayer spatialQueryResultLayer = new InMemoryFeatureLayer();
spatialQueryResultLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = new AreaStyle(new GeoSolidBrush(GeoColor.FromArgb(200, GeoColor.SimpleColors.PastelRed)));
spatialQueryResultLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle.OutlinePen.Color = GeoColor.StandardColors.Red;
spatialQueryResultLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
LayerOverlay resultsOverlay = new LayerOverlay("Results", false, TileType.SingleTile);
resultsOverlay.Layers.Add("Results", spatialQueryResultLayer);
resultsOverlay.TransitionEffect = TransitionEffect.Stretching;
myAreasMap.CustomOverlays.Add(resultsOverlay);
LayerOverlay roadsOverlay = (LayerOverlay)myAreasMap.CustomOverlays["Roads"];
ShapeFileFeatureLayer roadsLayer = (ShapeFileFeatureLayer)roadsOverlay.Layers["Roads"];
Feature rectangleFeature = rectangleLayer.InternalFeatures["Rectangle"];
roadsLayer.Open();
Collection<feature> spatialQueryResults = roadsLayer.QueryTools.GetFeaturesContaining(rectangleFeature, new string[0]);
roadsLayer.Close();
spatialQueryResultLayer.InternalFeatures.Clear();
spatialQueryResultLayer.Open();
foreach (Feature feature in spatialQueryResults)
{
spatialQueryResultLayer.InternalFeatures.Add(feature.Id, feature);
}
spatialQueryResultLayer.Close();
resultsOverlay.Redraw();
}
While I appreciate that this is probably not the best way to do things, I'm simply trying to get a working example first. The code runs fine, and the roads render fine when displayed onscreen, however when I run the query code the spacialQueryResults structure is always empty despite the rectangle being correctly drawn in a layer over the relevant section of roads.
