Listview tooltip not showing

[clausowitz]

I want to show a tooltip on my listview. I implemented the code. Its called correctly however no Tooltip is shown.

ListView1.ShowItemToolTips = True
Private Sub ListView1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles ListView1.MouseMove

        Dim thisItem As ListViewItem = ListView1.GetItemAt(e.X, e.Y)
        If Not IsNothing(thisItem) Then
            ToolTip1.SetToolTip(ListView1, thisItem.Text)
        Else
            ToolTip1.RemoveAll()
        End If
    End Sub

    Private Sub ListView1_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles ListView1.MouseLeave
        ToolTip1.RemoveAll()
    End Sub