How to detect when the client is back online

[zerak]

The application that I am trying to build basically try to do this:
Each time the user updates a record, the app will check to see if the machine is online (LAN, internet, etc). If it is online, it will send the record to the server, if it is not online, then it will save it locally and when the user goes online, it will send the record to the server.
So I am thinking to send the data to the server. If that fails, then I can assume that the user is offline or the server is down, which is the same in my situation. Now the main problem is how to know when the user is back online. There must be a system event that gets fired when you go online. I am trying to know the name of that event and how to use it. I appreciate your help.

[James Stanich]

Private Declare Function InternetGetConnectedState Lib "wininet.dll" (ByRef lpSFlags As Long, ByVal dwReserved As Long) As Long
 
If InternetGetConnectedState(0, 0) Then
 
    MsgBox "Online"
 
Else
 
    MsgBox "Offline"
 
End If

[zerak]

So do I need to call "InternetGetConnectedState" all the time in order to know when the machine is back online?

[James Stanich]

My idea would be to check when database is to be updated.

If online update as such.

If offline, update locally.

When application is started, check to see if connected, if so , update the main database form the local copy...

[zerak]

Thanks James. I tried your code and it works. I am using windows XP. Do you know if most windows versions have "wininet.dll" ?

[James Stanich]

Good question. I mainly develop for NT/2000 client so I couldn't answer. Perhaps try posting in the General Vb Questions area?

Glad I could help (sort of )

[James Stanich]

Did you reslove this issue?

[zerak]

I didn’t have the time to work on it but I will post to the issue on general discusion for VB.