FileSystemWatcher 更新表单上的文本框

Question

大家好，我正在使用 FileSystemWatcher 检查 .ini 文件是否已更改。如果有，那么我希望我能够更新表单上的文本框。问题是它是一个共享函数，以便 FileSystemWatcher 工作，所以表单上的任何内容似乎都无法在该共享函数内访问？

我的代码：

Private Sub frmCamera_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim watcher As New FileSystemWatcher()

    watcher.Path = Application.StartupPath
    watcher.NotifyFilter = (NotifyFilters.LastAccess Or NotifyFilters.LastWrite Or NotifyFilters.FileName Or NotifyFilters.DirectoryName)
    watcher.Filter = "*.ini"
    watcher.SynchronizingObject = Me

    AddHandler watcher.Changed, AddressOf OnChanged
    watcher.EnableRaisingEvents = True
End Sub

Private Shared Sub OnChanged(source As Object, e As FileSystemEventArgs)
    Dim sb1 As New StringBuilder(500)
    Dim theButtonsName As String = ""

    GetPrivateProfileString("camera", "val1", "", sb1, sb1.Capacity, Application.StartupPath & "\savedData.ini")

    main.GetPrivateProfileString("camera", "val1", "", sb1, sb1.Capacity, Application.StartupPath & "\savedData.ini")

    Dim frm As frmCamera = DirectCast(DirectCast(source, FileSystemWatcher).SynchronizingObject, frmCamera)
    frm.TextBox1.Text = "debug: " & sb1.ToString
End Sub

我通过主表单调用上面的表单，如下所示：

Public Sub doStuff(ByVal what2Do As String)
   If Trim(lanSent(0)) = "camera" And Trim(lanSent(1)) = "show" Then
      theCam = New Threading.Thread(AddressOf ShowCam)

      theCam.SetApartmentState(Threading.ApartmentState.STA)
      theCam.Start()
   Else
     .....
   End If
End Sub

Private Shared Sub ShowCam()
    Dim ShowCam As New frmCamera
    ShowCam.ShowDialog()
End Sub

我想要完成的是，一旦它看到文本框在其中输入（TextBox1_TextChanged），就运行一些其他的东西。

任何帮助都会很好地解决我的这个问题！谢谢！

Answer 1

不确定这是否对您有用，因为我不知道您为什么使用共享事件处理程序，但是您可以尝试使用FileSystemWatcher.SynchronizingObject 属性，如果您将其设置为您的表单，您可以在您的共享方法中检索它。

Private Shared Sub OnChanged(source As Object, e As FileSystemEventArgs)
    Dim sb1 As New StringBuilder(500)
    Dim theButtonsName As String = ""
    GetPrivateProfileString("camera", "val1", "", sb1, sb1.Capacity, Application.StartupPath & "\savedData.ini")

    Dim frm As Form1 = DirectCast(DirectCast(source, FileSystemWatcher).SynchronizingObject, Form1)
    frm.TextBox1.Text = sb1.ToString
 End Sub

FileSystemWatcher 的初始化

 Dim watcher As New FileSystemWatcher
 watcher.Path = Application.StartupPath
 watcher.SynchronizingObject = Me  'Assigning your Forms Instance to the SychronizingObject
 watcher.NotifyFilter = (NotifyFilters.LastAccess Or NotifyFilters.LastWrite Or NotifyFilters.FileName Or NotifyFilters.DirectoryName)
 watcher.Filter = "*.ini"
 AddHandler watcher.Changed, AddressOf OnChanged
 watcher.EnableRaisingEvents = True