Private Sub ListViewMouseClick(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.MouseEventArgs)
 
Dim myTabPage As LVTabPage = CType(sender, LVTabPage)
 
      ' Datenzeile ermitteln
      Dim HitItem As ListViewHitTestInfo = myTabPage.ListView.HitTest( _
        e.Location)
 
' Ausgabe der geklickten Zelle
If Not HitItem.Item Is Nothing Then
         MsgBox("Mausklick erfolgte auf " & HitItem.SubItem.Text)
End If
 
End Sub

Public Class Form1
    Dim dat1, dat2, dat3, dat4 As String
    Dim Temp As String
    Dim all As String
    Dim zv As String, gg As String = ""
    Private Const sLetter As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    Private Sub ListViewMouseClick(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs)
        Dim myTabPage As LVTabPage = CType(sender, LVTabPage)
 
        ' Datenzeile ermitteln
        Dim HitItem As ListViewHitTestInfo = myTabPage.ListView.HitTest( _
          e.Location)
 
        ' Ausgabe der geklickten Zelle
        If Not HitItem.Item Is Nothing Then
            MsgBox("Mausklick erfolgte auf " & HitItem.SubItem.Text)
        End If
 
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
 
       For i As Int16 = 0 To 25
            Dim tp As New LVTabPage
            tp.Text = sLetter(i)
            tp.Name = "TabPage_" & sLetter(i)
            Me.TabControl1.TabPages.Add(tp)
        Next
 
        Dim myTabPage As LVTabPage = CType(Me.TabControl1.TabPages( _
          "TabPage_A"), _
          LVTabPage)
 
        With myTabPage.ListView
            .BeginUpdate()
            For Each sItem As String In My.Computer.FileSystem.GetDirectories( _
              "C:\Physiotherapie\Patienten")
 
                Dim All() As String = Split(sItem, ",")
 
                dat1 = All(0) : dat2 = All(1) : dat3 = All(2) : dat4 = All(3)
 
                dat1 = dat1.Substring(28)
                zv = (myTabPage.Name.Substring(8))
                gg = (dat1(0).ToString)
 
                If zv = gg Then
                    myTabPage.ListView.Items.Add(New ListViewItem(New String() _
                      {dat1, dat2, dat3, dat4}))
                End If
 
            Next
            .EndUpdate()
        End With
 
        myTabPage.ListView.Columns(0).Width = -1
        myTabPage.ListView.Columns(1).Width = -1
        myTabPage.ListView.Columns(2).Width = -1
        myTabPage.ListView.Columns(3).Width = -2
 
    End Sub
 
    Private Sub TabControl1_Selected(ByVal sender As System.Object, ByVal e As _
      System.Windows.Forms.TabControlEventArgs) Handles TabControl1.Selected
 
        Dim myTabPage As LVTabPage = CType(e.TabPage, LVTabPage)
 
        myTabPage.ListView.Items.Clear()
 
        For Each sItem As String In My.Computer.FileSystem.GetDirectories( _
          "C:\Physiotherapie\Patienten")
 
            Dim All() As String = Split(sItem, ",")
 
 
            dat1 = All(0) : dat2 = All(1) : dat3 = All(2) : dat4 = All(3)
 
            dat1 = dat1.Substring(28)
            zv = (myTabPage.Name.Substring(8))
            gg = (dat1(0).ToString)
 
            If zv = gg Then
                myTabPage.ListView.Items.Add(New ListViewItem(New String() _
                  {dat1, dat2, dat3, dat4}))
            End If
 
        Next
 
        myTabPage.ListView.Columns(0).Width = -1
        myTabPage.ListView.Columns(1).Width = -1
        myTabPage.ListView.Columns(2).Width = -1
        myTabPage.ListView.Columns(3).Width = -2
 
    End Sub
 
 
 
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Timer1.Tick
 
        ToolStripStatusLabel1.Text = Now
 
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
 
        Form2.Show()
 
    End Sub
 
End Class