Is it possible to create a standalone VB.Net desktop app using late binding of ArcObjects to avoid version dependencies that result from early binding?

ChristopherHeltzel — Thu, 15 Sep 2016 15:30:40 GMT

I have a simple program that connects to a personal geodatabase to check various feature class properties. Unfortunately the program cannot be installed on a client computer if it has a different version of ArcGIS Desktop than the one on my development computer (example: 10.3 on my computer and 10.2 or 10.4 on the client computer). I want to use late binding so the OneClick installation does not fail due to a different ArcGIS version.

The following early binding code works, but is version dependent:

Private Function OpenAccessWorkspace(ByVal sSourcePGDB as string) As ESRI.ArcGIS.Geodatabase.IWorkspace
Dim aoFactory As IWorkspaceFactory

Dim aoWorkspace As IWorkspace

aoFactory = New ESRI.ArcGIS.DataSourcesGDB.AccessWorkspaceFactory
aoWorkspace = aoFactory.OpenFromFile(sSourcePGDB, 0)

Return aoWorkspace
End Function

This late binding code fails at line 5 when setting aoWorkspace with error NullReferenceException: Object reference not set to an instance of an object.

Private Function OpenAccessWorkspace3(ByVal sSourcePGDB As String) As Object

Dim aoFactory As Object

Dim aoWorkspace As Object

aoFactory = CreateObject("esriDataSourcesGDB.AccessWorkspaceFactory")
aoWorkspace = aoFactory.OpenFromFile(sSourcePGDB, 0) ' ERROR

Return aoWorkspace
End Function

Can anyone confirm that it is possible to use late binding with ArcObjects? If so, can you tell what I am doing wrong?

Re: Is it possible to create a standalone VB.Net desktop app using late binding of ArcObjects to avoid version dependencies that result from early binding?

ChristopherHeltzel — Wed, 28 Sep 2016 12:49:14 GMT

I found the definitive answer at this link http://resources.esri.com/help/9.3/arcgisdesktop/com/COM/IntroToCOM.htm

“The object classes within the ESRI object libraries do not implement the IDispatch interface; this means that these object libraries cannot be used with late-binding scripting languages, such as JavaScript or VBScript, since these languages require that all COM servers accessed support the IDispatch interface.”

Although I am not using a scripting language, the end result is the same: ArcObjects does not implement the IDispatch interface and therefore does not support late binding.

topic Re: Is it possible to create a standalone VB.Net desktop app using late binding of ArcObjects to avoid version dependencies that result from early binding? in ArcObjects SDK Questions

Is it possible to create a standalone VB.Net desktop app using late binding of ArcObjects to avoid version dependencies that result from early binding?

Re: Is it possible to create a standalone VB.Net desktop app using late binding of ArcObjects to avoid version dependencies that result from early binding?