ClassName returns 
void. I am going to submit a bug report. 

The functions are indeed based on Visual Basic, but this is the documentation I have from the vendor. And no, I do not use External Functions - I insert Ole Custom Control. My application is deployed as 32 bit, the control is 32 bit as well. This is an event, not a method, as documented by OCX vendor:

DirList Event (WebDAV Control)
This event fires for each entry returned in a directory listing.

Sub webdavcontrol_DirList(ResourceURI As String, DisplayName As String, ContentLanguage As String, ContentLength As Long64, ContentType As String, LastModified As String)

Remarks
The DirList event is fired when a directory listing is received as a response to ListDirectory.

This is the previous version which works fine. In PB, I created a user object, and then in PB IDE  I do 'Insert' -> 'Control' -> 'Ole' -> 'Insert Control' tab, select version 2022 of the WebDav control.

You can see that for DirList event ContentLength is String. This is what I see in PB:

You can see that ContentLength is  a String and my code works. Now I try to use version 2024 of OCX control

Now in DirList event ContentLength is Any! And in PB:

I tried to change the return type of ContenLength to string, long, longlong, blob - then the event is not fired. I tried to keep Any data type and change Access to 'by reference'. Then the following code:

string ls_size

ls_size = contentlength // Causes runtime error:

The following:

longlong ll_size

ll_size = contentlength*1

ll_size = LongLong(contentlength) //this returns 0

ls_size = string(contentlength) //this returns empty string

I am out of ideas. 

It looks to me that you have supplied us with the Visual Basic prototypes for the before/after function calls, as those are not in PowerBuilder form. Can you please supply the External Function Declaration (EFD) that you used with the previous version as it was coded in PowerBuilder?

Not being a Visual Basic developer (well, not since VB 4, 30 years ago), I can make a guess that a Long64 datatype is a 64-bit integer, and that the new version of this function is supplying the memory address of a string. Is this correct?

Is your PB app deployed as a 32-bit app or as a 64-bit app?

If I were in your shoes, I would try changing the EFD in PowerBuilder so that this problematic argument's datatype is LongLong and see if that will allow the function call to interface with PB correctly. If so, then that is a positive step in the right direction.

Once that is working, the challenge then becomes obtaining the string at the memory address that is supplied.

There is an obscure form of the PowerScript String function that can be used to obtain a string value from a memory address, but I've never tried using it with a LongLong datatype. It is documented (even more obscurely) in the PB Help for the TriggerEvent and PostEvent PowerScript functions to use an address in a Long datatype. It is coded like this:

String ls_value
Long   ll_memory_address  // Assume this variable contains the address of a string value.

ls_value = String(ll_memory_address,"address")

If that does not work, then you'll likely need to call a Windows API function to obtain the string value. I (or others here in the Community) can assist with that, but first try what I have described and see if that works.

Best regards, John