Pitney Bowes MapXtreme - Manual (Page 345)

Chapter 19: Web Map Service
Understanding WMS Operations
MapXtreme v7.1 352 Developer Guide
GetMap
Once you know the capabilities of the WMS server, a GetMap request is issued to request a map
image of one or more of the WMS server’s map layers. Based on the WMS Server capabilities, a
GetMap request includes the following.
• Version–Request version
• Layers–one or more layers of map data
• Styles–display styles for rendering the layers. If this is not specified, default styles will be used.
• A bounding box–the area to be included in the map image in
• CRS–for WMS 1.3.0, or SRS (WMS 1.1.1) the coordinate reference system for the map in the
form of namespace:identifier.
• Output format–a MIME type such as GIF and PNG, for the output map image
• Output size–height and width in pixels of the map image
• Background color–a hexadecimal red-blue-green color value such as 0xFFFFFF (required when
transparency is true)
• Transparency–a true/false setting that indicates if the layer can be used as a transparent overlay
to other layers.
GetFeatureInfo
Once a GetMap request has been successfully completed the user may want further information
about the features included in the map. The GetFeatureInfo operation returns information regarding
the layers in the map and the queryable attributes of each layer. This operation is controlled by the
WMS Server, however, the server may not offer this capability.
Using MapXtreme as a WMS Client
You can request a WMS map image programmatically using the MapXtreme WMS client via
MapInfo.Data.TableInfoWMS. This section provides code snippets that illustrate how to use
MapXtreme as a WMS client. In addition, a WMSPreview sample application is located in the
Desktop samples folder after installation.
GetCapabilities
In MapXtreme, you do not call GetCapabilities directly. Your request for a map is contained in a call
using an WMSClient that takes a capabilities instance as input.
// build the capabilities
ICapabilities capabilities = WmsClientUtilities.GetCapabilities
(url, "1.3.0");
// create the WMS client
WmsClient wmsClient = new WmsClient(capabilities);
wmsClient.AddLayer("WORLD");
wmsClient.Srs = "EPSG:4326";
wmsClient.BGColor = Color.Blue;
wmsClient.MimeType = "image/gif";