我是这样处理双重创造问题的，忽略了第一个事件:

Private WithEvents fsw As New System.IO.FileSystemWatcher
Private complete As New List(Of String)

Private Sub fsw_Created(ByVal sender As Object, _
    ByVal e As System.IO.FileSystemEventArgs) Handles fsw.Created

    If Not complete.Contains(e.FullPath) Then
        complete.Add(e.FullPath)

    Else
        complete.Remove(e.FullPath)
        Dim th As New Threading.Thread(AddressOf hprocess)
        th.Start(e)

    End If

End Sub

这个解决方案适用于我的生产应用程序:

环境:

VB。Net Framework 4.5.2

手动设置对象属性:NotifyFilter = Size

然后使用下面的代码:

Public Class main
    Dim CalledOnce = False
    Private Sub FileSystemWatcher1_Changed(sender As Object, e As IO.FileSystemEventArgs) Handles FileSystemWatcher1.Changed
            If (CalledOnce = False) Then
                CalledOnce = True
                If (e.ChangeType = 4) Then
                    ' Do task...
                CalledOnce = False
            End If
        End Sub
End Sub

以下是我的解决方案，帮助我阻止事件被提出两次:

watcher.NotifyFilter = NotifyFilters.FileName | NotifyFilters.Size;

这里我只设置了文件名和大小的NotifyFilter属性。 watcher是FileSystemWatcher的对象。希望这能有所帮助。

这里有一个你可以尝试的新解决方案。很适合我。在已更改事件的事件处理程序中，以编程方式从设计器输出中删除处理程序(如果需要的话)，然后以编程方式将处理程序添加回来。例子:

public void fileSystemWatcher1_Changed( object sender, System.IO.FileSystemEventArgs e )
    {            
        fileSystemWatcher1.Changed -= new System.IO.FileSystemEventHandler( fileSystemWatcher1_Changed );
        MessageBox.Show( "File has been uploaded to destination", "Success!" );
        fileSystemWatcher1.Changed += new System.IO.FileSystemEventHandler( fileSystemWatcher1_Changed );
    }

我认为解决这个问题的最佳方案是使用响应式扩展 当你将事件转换为可观察对象时，你可以添加Throttling(..)(最初称为Debounce(..))

这里是示例代码

        var templatesWatcher = new FileSystemWatcher(settingsSnapshot.Value.TemplatesDirectory)
        {
            NotifyFilter = NotifyFilters.LastWrite,
            IncludeSubdirectories = true
        };

        templatesWatcher.EnableRaisingEvents = true;

        Observable.FromEventPattern<FileSystemEventHandler, FileSystemEventArgs>(
                addHandler => templatesWatcher.Changed += addHandler,
                removeHandler => templatesWatcher.Changed -= removeHandler)
            .Throttle(TimeSpan.FromSeconds(5))
            .Subscribe(args =>
            {
                _logger.LogInformation($"Template file {args.EventArgs.Name} has changed");
                //TODO do something
            });

如果你注册了OnChanged事件，那么在修改之前删除被监视的文件可能会起作用，只要你只需要监视OnChange事件。