How do I get events to execute on the "main thread"
- by William DiStefano
I have 2 classes, one is frmMain a windows form and the other is a class in vb.NET 2003.
frmMain contains a start button which executes the monitor function in the other class. My question is, I am manually adding the event handlers -- when the events are executed how do I get them to excute on the "main thread". Because when the tooltip balloon pops up at the tray icon it displays a second tray icon instead of popping up at the existing tray icon. I can confirm that this is because the events are firing on new threads because if I try to display a balloon tooltip from frmMain it will display on the existing tray icon.
Here is a part of the second class (not the entire thing):
Friend Class monitorFolders
Private _watchFolder As System.IO.FileSystemWatcher = New System.IO.FileSystemWatcher
Private _eType As evtType
Private Enum evtType
changed
created
deleted
renamed
End Enum
Friend Sub monitor(ByVal path As String)
_watchFolder.Path = path
'Add a list of Filter to specify
_watchFolder.NotifyFilter = IO.NotifyFilters.DirectoryName
_watchFolder.NotifyFilter = _watchFolder.NotifyFilter Or IO.NotifyFilters.FileName
_watchFolder.NotifyFilter = _watchFolder.NotifyFilter Or IO.NotifyFilters.Attributes
'Add event handlers for each type of event that can occur
AddHandler _watchFolder.Changed, AddressOf change
AddHandler _watchFolder.Created, AddressOf change
AddHandler _watchFolder.Deleted, AddressOf change
AddHandler _watchFolder.Renamed, AddressOf Rename
'Start watching for events
_watchFolder.EnableRaisingEvents = True
End Sub
Private Sub change(ByVal source As Object, ByVal e As System.IO.FileSystemEventArgs)
If e.ChangeType = IO.WatcherChangeTypes.Changed Then
_eType = evtType.changed
notification()
End If
If e.ChangeType = IO.WatcherChangeTypes.Created Then
_eType = evtType.created
notification()
End If
If e.ChangeType = IO.WatcherChangeTypes.Deleted Then
_eType = evtType.deleted
notification()
End If
End Sub
Private Sub notification()
_mainForm.NotifyIcon1.ShowBalloonTip(500, "Folder Monitor", "A file has been " + [Enum].GetName(GetType(evtType), _eType), ToolTipIcon.Info)
End Sub
End Class
