OgcWmtsLayer Class
A layer that displays map images from OpenGIS Web Map Tile Service (WMTS) servers and other tiled map services.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CEOgc assembly)
Syntax
public class OgcWmtsLayer : HttpLayerRemarks
An OgcWmtsLayer generates its presentation using tiled map images from OGC WMTS services and some other tiled map services.
Using WMTS, it can connect to servers implementing version 1.0.0 of the OpenGIS Web Map Tile Service Implementation Specification, see www.opengis.org for more information. RESTful (resource oriented) and KVP (key/value pair) interfaces are supported, but not SOAP. Styles are supported, but not themes.
In spite of its name, OgcWmtsLayer can also connect directly to servers using the slippy map tilenames scheme, supported by many Open Street Maps servers. See for instance https://wiki.openstreetmap.org/wiki/Tile_servers for a list of publicly accessible servers. To use such a server, the Url property should be specified as a template tile url to the service, containing template parameters {x}, {y} or {-y}, and {z}.
Finally, OgcWmtsLayer can also connect to and load maps from the Bing Maps service. If the Url property contains the hostname of the Bing Maps metadata service ("dev.virtualearth.net"), the OgcWmtsLayer will download metadata for the service to locate the correct Bing Maps tile servers, and then use those to download map images. See https://docs.microsoft.com/en-us/bingmaps/rest-services/imagery/get-imagery-metadata to retrieve the metadata URL. Please note that you must obtain your own Bing Maps API Key and supply it in the URL, see https://docs.microsoft.com/en-us/bingmaps/getting-started/bing-maps-dev-center-help/getting-a-bing-maps-key.
To use an OgcWmtsLayer you usually only need to set the Url property, to identify the service. Everything else will be configured automatically when the layer is being initialized. For servers using slippy map tilenames, you may also have to specify the MaxLevel property.
After an OgcWmtsLayer has been initialized you can access the layer hierarchy that is provided by the service through the Layers property which will contain a list of OgcWmtsServerLayer instances. The layer list itself is read-only and any attempt to insert or remove layers from it will result in an exception being thrown. You can however use it to enable/disable child layers, apply named styles, populate a GUI control and more. Please see OgcWmtsServerLayer for more information.
OgcWmtsLayer and TileLayer
In Carmenta Engine versions prior to 5.12, a OgcWmtsLayer was usually used inside a TileLayer, to make the fetching of map tiles asynchronous and to provide caching of the map images. But this caused some extra overhead and other issues, mainly because the tile layer and the WMTS service typically used different tiling schemes.
In version 5.12, OgcWmtsLayer has been much improved, and now manages its own asynchronous I/O requests and image caching, and it no longer requires a TileLayer. This gives a much better performance compared to the TileLayer solution.
TileLayer is aware of this fact and if it finds an OgcWmtsLayer as a child, it "leaves it alone" to handle its own updates. So you can still safely put your WMTS layers under a tile layer if you wish.
Inheritance Hierarchy
System.Object (not available in C#)
EngineObject
Layer
LayerSet
HttpLayer
OgcWmtsLayer
Platforms
Windows, Linux, Android
OgcWmtsLayer Members
The OgcWmtsLayer type has the following members.
Constructors
| Name | Description |
|---|---|
| OgcWmtsLayer | Creates a new instance of the OgcWmtsLayer class. |
Properties
| Name | Description |
|---|---|
| Asynchronous | Gets or sets a flag indicating if the layer should work in synchronous or asynchronous mode. |
| BlendMode | Gets or sets the blend mode that determines how the layer is combined with previously rendered layers. Inherited from Layer |
| CachePath | Gets or sets a directory on disk where tiles are cached. |
| CacheSize | Gets or sets the maximum amount of disk space used by the disk cache. |
| Condition | Gets or sets the Condition that determines whether the OgcWmtsLayer is drawn or not. Inherited from Layer |
| CoverageHint | Gets or sets a value that can assert that the visualization is fully opaque within the data extent. Inherited from Layer |
| Description | Gets or sets a short description of the layer. Inherited from Layer |
| DisableOnError | Gets or sets a value specifying if an error within the layer should automatically disable the layer, or throw an exception. Inherited from Layer |
| DisplayName | Gets or sets a display name for the layer. Inherited from Layer |
| Effects | List of effects Inherited from Layer |
| Enabled | Determines whether the OgcWmtsLayer is enabled or not. Inherited from Layer |
| EnabledDuringQuickUpdates | Determines whether the OgcWmtsLayer is temporarily turned off during mouse interactions. Inherited from Layer |
| Encoding | Gets or sets the encoding to use for requests to the WMTS service. |
| ExplicitLayers | Gets the list of layers that should be included in the map image. |
| ExplicitStyles | Gets the list of named styles for the layers in the map image |
| Format | Gets or sets the graphics format of the map image generated by the OGC WMTS service. |
| IsDisposed | Gets a value that tells whether the current OgcWmtsLayer has been disposed. Inherited from EngineObject |
| IsoMetadataDocument | Gets or sets the path or URL to an ISO 19139 metadata document for the layer. Inherited from Layer |
| Layers | Gets the child layers of this OgcWmtsLayer. Inherited from LayerSet |
| Legend | Gets or sets a map legend associated with this layer. Inherited from Layer |
| MaxLevel | Gets or sets the maximum tile level to request from a slippy maps tilenames service. |
| MaxScale | Gets or sets the highest inverted nominal scale in a 2D view, or the furthest distance in a 3D globe view, at which objects from this OgcWmtsLayer should be drawn. Inherited from Layer |
| MinScale | Gets or sets the lowest inverted nominal scale this OgcWmtsLayer should be drawn at. Inherited from Layer |
| Name | Gets or sets the name of the layer. Inherited from Layer |
| NamedStyles | Gets the list of named styles that can be enabled for the layer. Inherited from Layer |
| NativeHandle | Gets the native Carmenta Engine kernel object the current OgcWmtsLayer represents. Inherited from EngineObject |
| Opacity | Gets or sets a value that specifies the opacity of the layer. Inherited from Layer |
| Password | Gets or sets the password used for basic authentication by the OGC WMS/WMTS service. Inherited from HttpLayer |
| ServiceMonitorInterval | Starts a background thread that monitors the OGC service for changes. Inherited from HttpLayer |
| ThrowExceptions | Gets or sets a flag indicating if exceptions should be thrown when an error occurs. Inherited from HttpLayer |
| Timeout | Gets or sets a value that indicates how long the layer will wait for a response from the OGC WMS/WMTS server. Inherited from HttpLayer |
| Url | Gets or sets the URL to a web mapping service. Inherited from HttpLayer |
| User | Gets or sets the username used for basic authentication by the OGC WMS/WMTS service. Inherited from HttpLayer |
| IUserProperties.UserProperties | Gets the AttributeSet that contains the user properties. Inherited from IUserProperties |
| VendorSpecificParameters | Gets or sets any vendor specific parameters that are appended to all requests. |
Methods
| Name | Description |
|---|---|
| Clone | Creates a copy of an object. Inherited from EngineObject |
| Dispose | Releases the reference to the native Carmenta Engine kernel instance the EngineObject represents. Inherited from EngineObject |
| EnableStyle | Enables or disables a named style for the layer. Inherited from Layer |
| Equals | Determines whether this instance is equal to another. Inherited from EngineObject |
| FindChildObject | Overloaded. Finds the child object with the specified name. Inherited from Layer |
| FlushCache | Marks the layer as flushed which will release cached resources during the next update. Inherited from Layer |
| FlushDiskCache | Removes all tiles cached on disk. |
| GetChildObjects | Overloaded. Gets the child objects of the current object. Inherited from Layer |
| GetDataBounds | Calculates the bounds of all dataset coverages in the layer. Inherited from Layer |
| GetFeatureAttributes | Gets information about all attributes that may be present on features in this layer. Inherited from Layer |
| GetFeatures | Overloaded. Gets features from the layer and any child layers. Inherited from Layer |
| GetLastError | Gets the error message for the last error that occurred within the layer. Inherited from Layer |
| GetLocalizedDescription | Gets a localized version of the layer description in a specific language. Inherited from Layer |
| GetLocalizedDisplayName | Gets a localized version of the layer display name in a specific language. Inherited from Layer |
| GetLocalizedIsoMetadataDocument | Gets the path to an ISO 19139 metadata document for a specific language. Inherited from Layer |
| HasLocalizedDescription | Checks if a localized version of the layer description is available in a specific language. Inherited from Layer |
| HasLocalizedDisplayName | Checks if a localized version of the layer display name is available in a specific language. Inherited from Layer |
| HasLocalizedIsoMetadataDocument | Checks if an ISO 19139 metadata document is available for a specific language. Inherited from Layer |
| Initialize | Initializes the OgcWmtsLayer instance. |
| IsStyleEnabled | Checks if a certain style is enabled for the layer or not. Inherited from Layer |
| MoveLayer | Moves a child layer to a new position. Inherited from LayerSet |
| Reset | Resets the OgcWmtsLayer or OgcWmsLayer instance to its default state. Inherited from HttpLayer |
| SetLocalizedDescription | Sets a layer description in a specific language. Inherited from Layer |
| SetLocalizedDisplayName | Sets a layer display name in a specific language. Inherited from Layer |
| SetLocalizedIsoMetadataDocument | Sets the path to an ISO 19139 metadata document for the layer, for a specific language. Inherited from Layer |
Events
| Name | Description |
|---|---|
| EnabledChanged | Occurs when the value of the Enabled property has changed. Inherited from Layer |
| ServiceChanged | Occurs when the layer has detected changes to the OGC service. Inherited from HttpLayer |