Programmatically get Layer source properties DataType with ArcObjects?

Question

I am trying to access the DataType property of a Layer in the TOC in ArcMap. The layer is added from a web service as an IMapServerRESTLayer. The Data Type property is listed with Layer -> Properties -> source as in the following screen shot.

enter image description here

The map layer has a Type Of ICompositeLayer. It is a basemap.

Things I've tried.

It cannot be cast as a IFeatureLayer. I have looked at the Carto Object Model Diagram, and cannot find a DataLayer property on anything except IMobileLayerInfo. and a similar ServiceDataType on IImageServerLayer. Tried making interface casts toward these objects but failed.

Looked at using IComProperty Sheets ... managed to create an unpopulated version but think this not the way to go.

I am programming in VB.Net (but can read C#) in ArcGIS 10.2 using VS2010

Any ideas?

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Here is the code I have been using to test retrieve the layer and test it. This is the on click method for a command button within an ArcMap Addin. It's part of a bigger toolbar. There are comments on the outcome of various parts of the code.

 Protected Overrides Sub OnClick()
 Const csProceedureName As String = "cmdListBaseMap_OnClick"
 MsgBox("In " & csProceedureName & vbNewLine & My.ThisAddIn.Name & vbNewLine & " Version " & My.ThisAddIn.Version & vbNewLine & " Date " & My.ThisAddIn.Date)
 Try
 Dim pApp As IApplication
 Dim pMxDoc As IMxDocument
 Dim pMap As IMap
 Dim pView As IActiveView
 Dim resturl As String
 'resturl = "http://services.thelist.tas.gov.au/arcgis/rest/services/Basemaps/Topographic/ImageServer/?f=lyr&v=9.3" ' v1 ' works
 resturl = "http://services.thelist.tas.gov.au/arcgis/rest/services/Basemaps/Topographic/ImageServer/?f=lyr" ' v2 ' works
 'resturl = "http://services.thelist.tas.gov.au/arcgis/services/Basemaps/Topographic/ImageServer" ' v3 ' does not work, does not leave a connection
 ' there was a problem getting the interface to work. 
 ' In addition to carto needed to include ESRI.ArcGIS.DataSourceRaster
 Dim RESTLayer As IMapServerRESTLayer
 RESTLayer = New MapServerRESTLayer
 Dim pLayer As ILayer
 Dim pFLayer As IFeatureLayer
 Dim pGenProperties As ILayerGeneralProperties
 Dim Mouse_cursor As IMouseCursor = New MouseCursor
 Mouse_cursor.SetCursor(2)
 pApp = My.ArcMap.Application
 pMxDoc = pApp.Document
 pMap = pMxDoc.FocusMap
 pView = pMxDoc.ActiveView
 ' Use web HttpWebRequest to see if connection OK and so can retrieve file
 Dim request_json_url As String = "http://services.thelist.tas.gov.au/arcgis/rest/services/Basemaps/Topographic/ImageServer/?f=json"
 Dim request As HttpWebRequest = DirectCast(HttpWebRequest.Create(request_json_url), HttpWebRequest)
 Dim response As HttpWebResponse = DirectCast(request.GetResponse, HttpWebResponse)
 'MsgBox("Doing test " & response.StatusCode.ToString & " " & response.StatusDescription & " " & HttpStatusCode.OK.ToString)
 If response.StatusCode = HttpStatusCode.OK Then
 ' connection and response OK
 'MsgBox("Status Code " & response.StatusCode & vbNewLine & " Status description " & response.StatusDescription & vbNewLine & " Encoding " & response.CharacterSet)
 ' this is one method of getting the json file
 'Dim encoding As Text.Encoding = System.Text.Encoding.GetEncoding(response.CharacterSet)
 'Dim reader As New StreamReader(response.GetResponseStream(), encoding)
 'Dim streamtext As String = reader.ReadToEnd()
 'MsgBox(streamtext)
 '' use a webclient to check connection, the try cast does exception handling
 'Dim wc As WebClient = New WebClient
 'Dim response_client As String
 ' response_client = wc.DownloadString(request_json_url)
 ' MsgBox(response_client)
 ' Get basemap
 RESTLayer.Connect(resturl)
 RESTLayer.TransparentBackground(True)
 ' this cast works
 pLayer = TryCast(RESTLayer, ILayer)
 If pLayer Is Nothing Then
 MsgBox("Cast from MapServerRESTLayer to Ilayer failed")
 Else
 MsgBox("Cast from MapServerRESTLayer to Ilayer OK")
 End If
 'Dim pDataLayer As IDataLayer
 ''this cast works
 'pDataLayer = TryCast(RESTLayer, IDataLayer)
 'If pDataLayer Is Nothing Then
 ' MsgBox("Cast from MapServerRESTLayer to IDataLayer failed")
 'Else
 ' MsgBox("Cast from MapServerRESTLayer to IDataLayer OK -" & pDataLayer.DataSourceName.NameString & "-") ' Name is empty
 ' ' cast here fails: so no path to IIMageserver
 ' Dim pServerLayer As IImageServerLayer
 ' pServerLayer = TryCast(pDataLayer, IImageServerLayer)
 ' If pServerLayer Is Nothing Then
 ' MsgBox("Cast from MapServerRESTLayer to IDataLayer to IImageServerLayer failed")
 ' Else
 ' MsgBox("Cast from MapServerRESTLayer to IDataLayer to IImageServerLayer OK " & pServerLayer.ServiceInfo.ServiceDataType.ToString)
 ' End If
 'End If
 '' this cast fails
 'Dim pServerLayer As IImageServerLayer
 'pServerLayer = TryCast(RESTLayer, IImageServerLayer)
 'If pServerLayer Is Nothing Then
 ' MsgBox("Cast from MapServerRESTLayer to IImageServerLayer failed")
 'Else
 ' MsgBox("Cast from MapServerRESTLayer to IImageServerLayer OK " & pServerLayer.ServiceInfo.ServiceDataType.ToString)
 'End If
 '' this cast also fails
 'Dim pServerLayerA As IImageServerLayer
 'pServerLayerA = TryCast(pLayer, IImageServerLayer)
 'If pServerLayerA Is Nothing Then
 ' MsgBox("Cast from ILayer to IImageServerLayer failed")
 'Else
 ' MsgBox("Cast from ILayer to IImageServerLayer OK " & pServerLayerA.ServiceInfo.ServiceDataType.ToString)
 'End If
 ' This cast sequence fails at first cast
 'Dim pMapServerLayer As IMapServerLayer
 'pMapServerLayer = TryCast(RESTLayer, IMapServerLayer)
 'If pMapServerLayer Is Nothing Then
 ' MsgBox("Cast from MapServerRESTLayer to IMapServerLayer failed")
 'Else
 ' MsgBox("Cast from MapServerRESTLayer to IMapServerLayer OK")
 ' Dim pImageServerLayerC As IImageServerLayer
 ' pImageServerLayerC = TryCast(pLayer, IImageServerLayer)
 ' If pImageServerLayerC Is Nothing Then
 ' MsgBox("* Cast from IMapServerLayer to IImageServerLayer failed")
 ' Else
 ' MsgBox("* Cast from IMapServerLayer to IImageServerLayer OK " & pImageServerLayerC.ServiceInfo.ServiceDataType.ToString)
 ' End If
 'End If
 ' cast failed
 'Dim ImageServiceInfo As IImageServiceInfo
 'ImageServiceInfo = TryCast(pLayer, ImageServiceInfo)
 'If ImageServiceInfo Is Nothing Then
 ' MsgBox("Cast from ILayer to IImageServiceInfo failed")
 'Else
 ' MsgBox("Cast from ILayer to IImageServiceInfo OK " & vbNewLine & _
 ' " Service Data Type " & ImageServiceInfo.ServiceDataType & vbNewLine & _
 ' " Service Source Type " & ImageServiceInfo.ServiceSourceType & vbNewLine & _
 ' " Default Service Properties " & ImageServiceInfo.DefaultServiceProperties)
 'End If
 ' This works
 ' Returns the Description 
 ' this returns a string with 
 ' "Tasmania Topographic base map", "LIST web service"
 ' for services and conditions see URL to services and consitions pdf
 '
 'pGenProperties = TryCast(pLayer, ILayerGeneralProperties)
 'If pGenProperties Is Nothing Then
 ' MsgBox("No general properties")
 'Else
 ' MsgBox("Properties -" & pGenProperties.LayerDescription & "-")
 'End If
 '' This cast works
 'Dim pCompositeLayer As ICompositeLayer2
 'pCompositeLayer = TryCast(pLayer, ICompositeLayer2)
 'If pCompositeLayer Is Nothing Then
 ' MsgBox("Cast from ILayer to ICompositeLayer failed")
 'Else
 ' MsgBox("Cast from ILayer to ICompositeLayer OK " & pCompositeLayer.Count.ToString)
 'End If
 '' This cast also works
 'Dim pCompositeLayerA As ICompositeLayer2
 'pCompositeLayerA = TryCast(RESTLayer, ICompositeLayer2)
 'If pCompositeLayerA Is Nothing Then
 ' MsgBox("Cast from ReST to ICompositeLayer failed")
 'Else
 ' MsgBox("Cast from REST to ICompositeLayer OK " & pCompositeLayerA.Count.ToString)
 'End If
 ' add layer to map
 pMap.AddLayer(pLayer)
 pView.Refresh()
 ' both versions of the imported layer are ILayer, IDataLayer, ICompositeLayer 
 MsgBox("player " & pLayer.Name & " is of type " & LayerType(pLayer))
 MsgBox("RESTLayer " & pLayer.Name & " is of type " & LayerType(pLayer))
 pMxDoc.ActiveView.Refresh()
 MsgBox("Base map layer " & pLayer.Name & "has been added")
 Else
 MsgBox("ERROR ( " & csProceedureName & " ) " & response.StatusCode & vbNewLine & response.StatusDescription)
 End If
 Mouse_cursor.SetCursor(0)
 Catch ex As Exception
 MsgBox("Error " & ex.Message)
 End Try
End Sub
Protected Overrides Sub OnUpdate()
End Sub
Public Function LayerType(ByVal pLayer As ILayer) As String
 ' return layer TypeOf
 LayerType = ""
 If TypeOf pLayer Is ILayer Then
 LayerType = LayerType & " " & "ILayer"
 End If
 If TypeOf pLayer Is IACAcetateLayer Then
 LayerType = LayerType & " " & "IACAcetateLayer"
 End If
 If TypeOf pLayer Is IACImageLayer Then
 LayerType = LayerType & " " & "IACImageLayer"
 End If
 If TypeOf pLayer Is IACFeatureLayer Then
 LayerType = LayerType & " " & "IACFeatureLayer"
 End If
 If TypeOf pLayer Is IACFeatureLayer Then
 LayerType = LayerType & " " & "IACFeatureLayer"
 End If
 If TypeOf pLayer Is IACLayer Then
 LayerType = LayerType & " " & "IACLayer"
 End If
 If TypeOf pLayer Is IAnnotationLayer Then
 LayerType = LayerType & " " & "IAnnotationLayer"
 End If
 If TypeOf pLayer Is IAnnotationSublayer Then
 LayerType = LayerType & " " & "IAnnotationSublayer"
 End If
 If TypeOf pLayer Is ICadastralFabricLayer Then
 LayerType = LayerType & " " & "ICadastralFabricLayer"
 End If
 If TypeOf pLayer Is ICadLayer Then
 LayerType = LayerType & " " & "ICadLayer"
 End If
 If TypeOf pLayer Is ICompositeGraphicsLayer Then
 LayerType = LayerType & " " & "ICompositeGraphicsLayer"
 End If
 If TypeOf pLayer Is ICompositeLayer Then
 LayerType = LayerType & " " & "ICompositeLayer"
 End If
 If TypeOf pLayer Is ICoverageAnnotationLayer Then
 LayerType = LayerType & " " & "ICoverageAnnotationLayer"
 End If
 If TypeOf pLayer Is IDataLayer Then
 LayerType = LayerType & " " & "IDataLayer"
 End If
 If TypeOf pLayer Is IDimensionLayer Then
 LayerType = LayerType & " " & "IDimensionLayer"
 End If
 If TypeOf pLayer Is IFDOGraphicsLayer Then
 LayerType = LayerType & " " & "IFDOGraphicsLayer"
 End If
 If TypeOf pLayer Is IFeatureLayer Then
 LayerType = LayerType & " " & "IFeatureLayer"
 End If
 If TypeOf pLayer Is IGdbRasterCatalogLayer Then
 LayerType = LayerType & " " & "IGdbRasterCatalogLayer"
 End If
 If TypeOf pLayer Is IGeoFeatureLayer Then
 LayerType = LayerType & " " & "IGeoFeatureLayer"
 End If
 If TypeOf pLayer Is IGraphicsLayer Then
 LayerType = LayerType & " " & "IGraphicsLayer"
 End If
 If TypeOf pLayer Is IGroupLayer Then
 LayerType = LayerType & " " & "IGroupLayer"
 End If
 If TypeOf pLayer Is IIMSMapLayer Then
 LayerType = LayerType & " " & "IIMSMapLayer"
 End If
 If TypeOf pLayer Is IIMSSubLayer Then
 LayerType = LayerType & " " & "IIMSSubLayer"
 End If
 If TypeOf pLayer Is IImageServerLayer Then
 LayerType = LayerType & " " & "IImageServerLayer"
 End If
 If TypeOf pLayer Is IImageServerLayer2 Then
 LayerType = LayerType & " " & "IImageServerLayer2"
 End If
 If TypeOf pLayer Is IImageServerLayer3 Then
 LayerType = LayerType & " " & "IImageServerLayer3"
 End If
 If TypeOf pLayer Is IMapServerLayer Then
 LayerType = LayerType & " " & "IMapServerLayer"
 End If
 If TypeOf pLayer Is IMapServerSublayer Then
 LayerType = LayerType & " " & "IMapServerSublayer"
 End If
 If TypeOf pLayer Is INetworkLayer Then
 LayerType = LayerType & " " & "INetworkLayer"
 End If
 If TypeOf pLayer Is IRasterCatalogLayer Then
 LayerType = LayerType & " " & "IRasterCatalogLayer"
 End If
 If TypeOf pLayer Is IRasterLayer Then
 LayerType = LayerType & " " & "IRasterLayer"
 End If
 If TypeOf pLayer Is ITemporaryLayer Then
 LayerType = LayerType & " " & "ITemporaryLayer"
 End If
 If TypeOf pLayer Is ITerrainLayer Then
 LayerType = LayerType & " " & "ITerrainLayer"
 End If
 If TypeOf pLayer Is ITinLayer Then
 LayerType = LayerType & " " & "ITinLayer"
 End If
 If TypeOf pLayer Is ITopologyLayer Then
 LayerType = LayerType & " " & "ITopologyLayer"
 End If
 If TypeOf pLayer Is IWMSGroupLayer Then
 LayerType = LayerType & " " & "IWMSGroupLayer"
 End If
 If TypeOf pLayer Is IWMSLayer Then
 LayerType = LayerType & " " & "IWMSLayer"
 End If
 If TypeOf pLayer Is IWMSMapLayer Then
 LayerType = LayerType & " " & "IWMSMapLayer"
 End If
 'Else
 ' LayerType = "UnKnown"
 'End If
End Function

• TazAstroSpacial: Here is some code that I have been using:<br/>

Answer 1

I can check the URL in your snapshot and say the layer you are trying to work with is an ImageServer Layer.

http://services.thelist.tas.gov.au/arcgis/rest/services/Basemaps/Topographic/ImageServer

You can not access an imageserver layer as a feature layer.

You can only access map server layers that have "Feature Access" enabled, as a feature layer. (e.g. Cast them to IFeatureLayer)

• TazAstroSpacial: Yes, I had discovered that via another forum, and trying various casts ie " It cannot be cast as a IFeatureLayer.".
• TazAstroSpacial: I test the TypEOf the layer once it is ArcMap TOC. That returns that the layer is an ICompositeLayer. Not as I expected an IImageServerLayer. In fact a cast (QI) to an IImageServerLayer fails. The ArcMap property dialog shows that it is in PNG format.
• Farid Cheraghi: It must be an IImageServerLayer. make sure your layer is not under a group layer (ICompositeLayer). Cast the layer to IImageServerLayer and see whether it is null or not.
• TazAstroSpacial: Done that. I have cast the resulting layer as a IImageServerLayer and the result is null. I have tested the TypOf for the layer, including all 3 versions of IImageService layer. The only type the layer matches is ICompositeLayer). What is really strange is that the sub layer count " pCompositeLayer.Count.ToString " is zero.
• TazAstroSpacial: The CompositeLayer cast is a distraction. The imported layer is TypeOf ILayer, or ICompositeLayer or IDataLayer and NOT IImageServerLayer. See the code.