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

主要原因是 第一个事件的最后一次访问时间是当前时间(文件写入或更改时间)。 第二个事件是文件最初的最后一次访问时间。 我在代码下解决。

        var lastRead = DateTime.MinValue;

        Watcher = new FileSystemWatcher(...)
        {
            NotifyFilter = NotifyFilters.FileName | NotifyFilters.LastWrite,
            Filter = "*.dll",
            IncludeSubdirectories = false,
        };
        Watcher.Changed += (senderObject, ea) =>
        {
            var now = DateTime.Now;
            var lastWriteTime = File.GetLastWriteTime(ea.FullPath);

            if (now == lastWriteTime)
            {
                return;
            }

            if (lastWriteTime != lastRead)
            {
                // do something...
                lastRead = lastWriteTime;
            }
        };

        Watcher.EnableRaisingEvents = true;

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

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。

好吧，这是我如何只引发一个事件的解决方案:

FileSystemWatcheк watcher = new FileSystemWatcher();

//'path' - path to the file that has been modified.
watcher.Changed += (s, e) => FileChanged(path);

这里是FileChanged实现

//count is our counter to triger when we can raise and when not.
private int count = 0;
private void FileChanged(string path)
{
   if (count % 2 == 0)
     {
       //code here
     }

     count ++;
}

我只想对最后一个事件做出反应，以防万一，也对linux文件更改，它似乎在第一次调用时文件是空的，然后在下一个调用时再次填充，不介意浪费一些时间，以防操作系统决定做一些文件/属性更改。

我在这里使用。net async来帮助我做线程。

    private static int _fileSystemWatcherCounts;
    private async void OnChanged(object sender, FileSystemEventArgs e)
    {
        // Filter several calls in short period of time
        Interlocked.Increment(ref _fileSystemWatcherCounts);
        await Task.Delay(100);
        if (Interlocked.Decrement(ref _fileSystemWatcherCounts) == 0)
            DoYourWork();
    }