如何识别触发事件的FileSystemWatcher对应的TabPage或子窗体？

要实现事件触发时识别对应的TabPage或子窗体，有两种直接可行的方法：

方法一：利用Tag属性建立关联 #

控件的Tag属性可以存储任意对象，我们可以把FileSystemWatcher所属的子窗体或TabPage存入其中，在事件处理时取出使用。

步骤1：修改主窗体中FileSystemWatcher的初始化代码 #

在创建Fsw时，将关联的子窗体存入Tag，同时修正事件绑定的对象（原代码中绑定了w.Watcher的事件，但实际初始化的是子窗体的Fsw，两者需统一）：

Private Sub CreateTabPageWatcher(w As ClsCfgWatcher)
    ' 添加TabPage代码不变...

    ' 创建子窗体代码不变...

    With f
        ' 控件赋值代码不变...

        ' 创建FilesystemWatcher并设置Tag
        .Fsw = New FileSystemWatcher With {
                .Path = w.Path,
                .Filter = w.Filter,
                .IncludeSubdirectories = w.IncludeSubdirs,
                .NotifyFilter = DirectCast(w.NotifyFilter, NotifyFilters),
                .Tag = f ' 将当前子窗体存入Tag
                }

        ' 绑定子窗体Fsw的事件，而非w.Watcher
        AddHandler f.Fsw.Created, AddressOf Fsw_Event
        AddHandler f.Fsw.Changed, AddressOf Fsw_Event
        AddHandler f.Fsw.Renamed, AddressOf Fsw_Event
        AddHandler f.Fsw.Deleted, AddressOf Fsw_Event

        f.Fsw.EnableRaisingEvents = True
    End With
End Sub

步骤2：修改事件处理程序 #

在主窗体的Fsw_Event中，从sender取出FileSystemWatcher，再通过Tag获取子窗体和对应的TabPage：

Private Sub Fsw_Event(sender As Object, e As FileSystemEventArgs)
    If e.FullPath <> "" Then
        ' 转换sender为FileSystemWatcher对象
        Dim fsw = DirectCast(sender, FileSystemWatcher)
        ' 从Tag取出关联的子窗体
        Dim childForm = DirectCast(fsw.Tag, FrmCfgWatcher)
        ' 通过子窗体的Parent属性获取所在TabPage
        Dim tabPage = DirectCast(childForm.Parent, TabPage)

        ' 现在可以访问子窗体控件和TabPage信息
        Dim sCmd As String = childForm.TxtCommand.Text
        ' 示例：输出TabPage名称
        ' MessageBox.Show($"事件来自TabPage：{tabPage.Text}")
    End If
End Sub

方法二：将事件逻辑封装到子窗体内部 #

把FileSystemWatcher的初始化和事件处理都放在子窗体中，天然就能直接访问自身控件和所在TabPage，代码封装性更好。

步骤1：修改子窗体FrmCfgWatcher #

添加初始化方法，内部完成Watcher配置和事件绑定：

Public Class FrmCfgWatcher
    Public Fsw As FileSystemWatcher

    ' 添加初始化方法，接收配置参数
    Public Sub InitializeWatcher(w As ClsCfgWatcher)
        ' 设置控件值
        TxtName.Text = w.Name
        TxtPath.Text = w.Path
        CbxSubDirs.Checked = w.IncludeSubdirs
        TxtFilter.Text = w.Filter

        TxtCommand.Text = w.ActionCommand
        TxtParameter.Text = w.ActionParameter
        TxtWorkingDir.Text = w.ActionWorkingDir

        ' 初始化FileSystemWatcher
        Fsw = New FileSystemWatcher With {
            .Path = w.Path,
            .Filter = w.Filter,
            .IncludeSubdirectories = w.IncludeSubdirs,
            .NotifyFilter = DirectCast(w.NotifyFilter, NotifyFilters)
        }

        ' 绑定自身的事件处理程序
        AddHandler Fsw.Created, AddressOf Fsw_Event
        AddHandler Fsw.Changed, AddressOf Fsw_Event
        AddHandler Fsw.Renamed, AddressOf Fsw_Event
        AddHandler Fsw.Deleted, AddressOf Fsw_Event

        Fsw.EnableRaisingEvents = True
    End Sub

    Private Sub Fsw_Event(sender As Object, e As FileSystemEventArgs)
        If e.FullPath <> "" Then
            ' 直接访问自身控件
            Dim sCmd As String = Me.TxtCommand.Text
            ' 获取所在TabPage
            Dim tabPage = DirectCast(Me.Parent, TabPage)
            ' 后续逻辑处理
        End If
    End Sub
End Class

步骤2：简化主窗体代码 #

主窗体只需创建TabPage和子窗体，调用初始化方法即可：

Private Sub CreateTabPageWatcher(w As ClsCfgWatcher)
    ' 添加TabPage代码不变...

    Dim f As New FrmCfgWatcher With {
        .TopLevel = False,
        .Anchor = AnchorStyles.Right Or AnchorStyles.Left Or AnchorStyles.Top Or AnchorStyles.Bottom,
        .Width = tp.Width, ' 改为使用当前TabPage的尺寸更准确
        .Height = tp.Height
    }
    tp.Controls.Add(f)
    f.Show()

    ' 调用子窗体初始化方法
    f.InitializeWatcher(w)
End Sub

内容的提问来源于stack exchange，提问作者Tobias G.