FileSystemWatcher Changed Event [resolved]

Hey guys, this is probably a simple question, but I am new to VB .net....

I have a FileSystemWatcher object in a Module and it is declared in that Module as public. The variable name is FileWatch. I also have a FileWatch.Changed() event in the same module, but it gives me an error whenever I try to compile:

error BC30506: Handles clause requires a WithEvents variable.

That error points to:

VB Code:

Public Sub FileWatch_Changed(ByVal sender As System.Object, ByVal e As System.IO.FileSystemEventArgs) Handles FileWatch.Changed

I know it's because it is in a module, and not in a form's code, but what do I add with WithEvents?

Thanks,
jonwondering

I don't know the answer.

However, the error sorta tells you the error.

If I were to guess, when you declare it, put withevents someone in the declaration.

I don't even know what that means, but I have seen and debugged programs where that was used.

- Josh

To use the FileSystemWatcher tool, you may add it to the form like a timer or ToolTip. Or when you declare the object manually and want to use its event than declare it with the WithEvents keyword.

Dim WithEvents FileWatch As IO.FileSystemWatcher

That solved the compiling problem, but when in the same module I do this:

VB Code:

FileWatch.NotifyFilter = FileWatch.LastAccess

then, application crashes at runtime saying Object reference not set to an instance of an object....

Add the New Keyword in the declaration ...

Dim WithEvents FileWatch As IO.FileSystemWatcher = New IO.FileSystemWatcher

Yeah that works. Thank you very much...

But now for some reason the FileWatch.Changed event is not working at all - it is not executed... could it be because it's located in a module?

Thanks

Have you set the

FileWatch.EnableRaisingEvents = True

It should look like this ....

VB Code:

Private WithEvents FileWatch As IO.FileSystemWatcher
 
Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    FileWatch = New IO.FileSystemWatcher("C:\Toto")
    FileWatch.NotifyFilter = IO.NotifyFilters.FileName
    FileWatch.EnableRaisingEvents = True
 
End Sub

Oh yes. I am sorry - the last one was my stupid mistake. I fixed it now. Thanks for your help Zakary!

Your are welcome :wave: