vb.net - 检查文件夹中是否有新文件

Question

我需要监视文件夹以查看何时创建新文件，然后处理文件并存档。

它是我正在努力解决的新文件的实际检测...我知道我需要查看 FileSystemWatcher 的东西，但想知道是否有人知道它以这种方式使用的任何示例来帮助我开始？

假设我的文件夹是“C:\Temp\”，我需要在任何带有“.dat”扩展名的文件出现时立即知道。

抱歉，这个含糊的问题，我只是无法通过各种谷歌搜索找到我要找的东西。

提前致谢

Answer 1

您可以使用FileSystemWatcher Class为此:它监听文件系统更改通知，并在目录或目录中的文件发生更改时引发事件。

Imports System
Imports System.IO
Imports System.Diagnostics

Public watchfolder As FileSystemWatcher

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    watchfolder = New System.IO.FileSystemWatcher()
    watchfolder.Path = "d:\pdf_record\"
    watchfolder.NotifyFilter = IO.NotifyFilters.DirectoryName
    watchfolder.NotifyFilter = watchfolder.NotifyFilter Or IO.NotifyFilters.FileName
    watchfolder.NotifyFilter = watchfolder.NotifyFilter Or IO.NotifyFilters.Attributes
    AddHandler watchfolder.Changed, AddressOf logchange
    AddHandler watchfolder.Created, AddressOf logchange
    AddHandler watchfolder.Deleted, AddressOf logchange
    AddHandler watchfolder.Renamed, AddressOf logrename
    watchfolder.EnableRaisingEvents = True
End Sub


Private Sub logchange(ByVal source As Object, ByVal e As System.IO.FileSystemEventArgs)
    If e.ChangeType = IO.WatcherChangeTypes.Changed Then
        MsgBox("File " & e.FullPath & " has been modified" & vbCrLf)
    End If
    If e.ChangeType = IO.WatcherChangeTypes.Created Then
        MsgBox("File " & e.FullPath & " has been created" & vbCrLf)
    End If
    If e.ChangeType = IO.WatcherChangeTypes.Deleted Then
        MsgBox("File " & e.FullPath & " has been deleted" & vbCrLf)
    End If
End Sub

Public Sub logrename(ByVal source As Object, ByVal e As System.IO.RenamedEventArgs)
    MsgBox("File" & e.OldName & " has been renamed to " & e.Name & vbCrLf)
End Sub