The simplest might be a timer control at the client. When it timesout, it could fire a procedure to evaluate the file for changes in size.

There is also an EVENTHANDLER in VFP 8. Sergey posted this pointer a few hundred threads back:

See Re: Detecting files in a folder Thread #809703 Message #809774


>Ok then,
>
>The server app and client app can share an external file. That could work.
>
>Let's just say that the server app writes the jpg file names, collected by the activeX control, to an xml file or dbf. What event can fire so that the client knows to go and read the xml or dbf that the server wrote to? And... and thoughts on how the client registers intself with the server app.
>
>Neil
>
>>>Hi,
>>>
>>>How do you set up 2 vfp apps so that one is a server and one is a client.
>>>How does the client application register itself with the server application so the server knows who to communicate with?
>>
>>I think servers are only aware of the session, and not the particulars of a specific client. They may just return info through the reference instanciated by by the client:
>>
>>oMyServer=CREATEOBJECT('Server')
>>
>>Typically, the client wiill ask the server for stuff. There are some methods the server can use to PUSH stuff to the client. In VFP 6, the only guy we had was COMRETURNERROR. More recent versions of VFP have evolved with Event Handlers - but nothing as straight forward as a 'COMRETURNEVENT' and 'ONEVENT' systax
>>
>>The server can write info keyed for a particular client to a file. The client, can access that info on demand or through some kind of client side timer event.
>>
>>>
>>>I host an activeX control in a vfp form that is basically an image browser. I can point the control to any directory and it will display a thumb nail list of all of the jpg files that are present. The jpg file names are stored in a collection of the activex control that I access in a for - endfor loop.
>>>
>>>I made a little project and generated a compiled exe that works fine. I would like to use this exe as a generic image browser. I would like to have it sitting on the taskbar waiting for me to maximize it. How do I get this stand-a-lone project to host information, ie:file names, to a seperately running vfp client. I guess that's really the question. How do you set up 2 vfp apps so that one is a server, one is a client and how does the client register itself with the server application?
>>
>>The server registers itself with the OS, and the client requests a session. It may be up to the client to retain specifics related to it's transactions with the server.
>>
>>Check out the "Timer" control.
>>
>>>
>>>Thanx,
>>>Neil