I am using the MapShapeLayer from the MapShapes sample. I would like to use the 4236 projection for the layer. However, my base layer is VirtualEarth which uses a different projection. On the web edition discussion forum there is a thread talking about how you can set the FeatureSource.Projection of a layer in order to allow a mixture of projections on the same map. Does this apply to the MapShapeLayer, and what do I need to do specifically to make this work for the MapShapeLayer?
Thanks!
Gregory,
If I am not misunderstanding something, what you are trying to use it the sample from following code project:
code.thinkgeo.com/projects/show/mapshapes
Then Just try following updated MapShapeLayer.
class MapShapeLayer : Layer
{
private Dictionary<string, MapShape> mapShapes;
private Projection projection;
public MapShapeLayer()
{
mapShapes = new Dictionary<string, MapShape>();
}
public Projection Projection
{
get { return projection; }
set { projection = value; }
}
// Here is where you place all of your map shapes.
public Dictionary<string, MapShape> MapShapes
{
get { return mapShapes; }
}
// This is a required overload of the Layer. As you can see we simply
// loop through all of our map shapes and then choose the correct zoom level.
// After that, the zoom level class takes care of the heavy lifiting. You
// have to love how easy this framework is to re-use.
protected override void DrawCore(GeoCanvas canvas, Collection<SimpleCandidate> labelsInAllLayers)
{
foreach (string mapShapeKey in mapShapes.Keys)
{
MapShape mapShape = mapShapes[mapShapeKey];
if (projection != null)
{
Feature newFeature = projection.ConvertToExternalProjection(mapShape.Feature);
mapShape.Feature = newFeature;
}
ZoomLevel currentZoomLevel = mapShape.ZoomLevels.GetZoomLevelForDrawing(canvas.CurrentWorldExtent, canvas.Width,GeographyUnit.Meter);
if (currentZoomLevel != null)
{
if (canvas.CurrentWorldExtent.Intersects(mapShape.Feature.GetBoundingBox()))
{
currentZoomLevel.Draw(canvas, new Feature[] { mapShape.Feature }, new Collection<SimpleCandidate>(), labelsInAllLayers);
}
}
}
}
Use age:
// Add the worldLayer to the MapEngine
worldLayer = new ShapeFileFeatureLayer(@"C:\bak\codethinkgeocom\MapShapes_090728\MapShapes\Data\Countries02.shp", ShapeFileReadWriteMode.ReadOnly);
worldLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = AreaStyles.County1;
worldLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
string str1 = Proj4Projection.GetEpsgParametersString(4326);
string str2 = Proj4Projection.GetGoogleMapParametersString();
worldLayer.FeatureSource.Projection = new Proj4Projection(str1, str2);
mapEngine.StaticLayers.Add("WorldLayer", worldLayer);
worldLayer.Open();
mapEngine.CurrentExtent = new RectangleShape(-10000000, 10000000, 10000000, -10000000);
worldLayer.Close();
// This is just a code snippet to show you how the new
// layer should be used.
// Add the mapShapeLayer to the MapEngine
MapShapeLayer mapShapeLayer = new MapShapeLayer();
MapShape mapShape1 = new MapShape(new Feature(-50, 42));
mapShape1.ZoomLevels.ZoomLevel01.DefaultPointStyle = new PointStyle(new GeoImage(@"C:\bak\codethinkgeocom\MapShapes_090728\MapShapes\Data\Cargo Plane.png"));
mapShape1.ZoomLevels.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
mapShapeLayer.MapShapes.Add("1", mapShape1);
MapShape mapShape2 = new MapShape(new Feature(50, 39));
mapShape2.ZoomLevels.ZoomLevel01.DefaultPointStyle = new PointStyle(new GeoImage(@"C:\bak\codethinkgeocom\MapShapes_090728\MapShapes\Data\China.png"));
mapShape2.ZoomLevels.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
mapShapeLayer.MapShapes.Add("2", mapShape2);
mapShapeLayer.Projection = new Proj4Projection(str1, str2);
mapShapeLayer.Projection.Open();
mapEngine.StaticLayers.Add("MapShapeLayer", mapShapeLayer);
DrawImage();
Of course, a better solution is just rewreite the MapShapeLayer as following way:
1) Change the inheritance for MapShapeLayer from FeatureLayer instead of Layer directly.
2) Add a MapShapeFeatureSource, hook it up to MapShapeLayer.
Any more questions just feel free to let me know.
Thanks.
Yale