/// <summary>
/// Determines the map units for the map
/// </summary>
/// <param name="map">The map to find map units for</param>
/// <param name="callback">The method to invoke once map units have been retrieved</param>
/// <param name="failedCallback">The method to invoke when map unit retrieval fails</param>
public static void GetMapUnitsAsync(this Map Map, Action <MapUnit> callback,
Action <object, ExceptionEventArgs> failedCallback = null)
{
if (Map != null)
{
Layer layer = Map.Layers.FirstOrDefault();
if (layer != null)
{
ESRI.ArcGIS.Client.Bing.TileLayer tiledLayer = layer as ESRI.ArcGIS.Client.Bing.TileLayer;
if (tiledLayer != null)
{
// Bing is web mercator
callback(Core.DataSources.MapUnit.Meters);
}
else
{
ESRI.ArcGIS.Client.Toolkit.DataSources.OpenStreetMapLayer osmLayer = layer as ESRI.ArcGIS.Client.Toolkit.DataSources.OpenStreetMapLayer;
if (osmLayer != null)
{
// Open Streem map is web mercator
callback(Core.DataSources.MapUnit.Meters);
}
else
{
// ArcGIS Server Base Map
string layerUrl = null;
ArcGISTiledMapServiceLayer agsTiledlayer = layer as ArcGISTiledMapServiceLayer;
if (agsTiledlayer != null)
{
layerUrl = agsTiledlayer.Url;
}
else
{
ArcGISDynamicMapServiceLayer agsDynamicLayer = layer as ArcGISDynamicMapServiceLayer;
if (agsDynamicLayer != null)
{
layerUrl = agsDynamicLayer.Url;
}
else
{
ArcGISImageServiceLayer agsImageLayer = layer as ArcGISImageServiceLayer;
if (agsImageLayer != null)
{
layerUrl = agsImageLayer.Url;
}
}
}
if (!string.IsNullOrWhiteSpace(layerUrl))
{
DataSourceProvider agsDataSource = new DataSourceProvider();
IBaseMapDataSource dataSource = agsDataSource.CreateDataSourceForBaseMapType(BaseMapType.ArcGISServer) as IBaseMapDataSource;
dataSource.GetMapServiceMetaDataCompleted += (o, args) =>
{
callback(args.MapUnit);
};
dataSource.GetMapServiceMetaDataFailed += (o, args) =>
{
if (failedCallback != null)
{
failedCallback(Map, args);
}
};
dataSource.GetMapServiceMetaDataAsync(layerUrl, null);
return;
}
}
}
}
}
}