Tıkladığım pencere ismini nasıl bulurum?

Imports System.Runtime.InteropServices

Public Class Form1
    <DllImport("user32.dll", SetLastError:=True)>
    Private Shared Function GetForegroundWindow() As IntPtr
    End Function
    <DllImport("user32.dll", EntryPoint:="GetWindowThreadProcessId")>
    Private Shared Function GetWindowThreadProcessId(<InAttribute()> ByVal hWnd As IntPtr, ByRef lpdwProcessId As Integer) As Integer
    End Function
    <DllImport("user32.dll")>
    Shared Function GetAsyncKeyState(ByVal vKey As System.Windows.Forms.Keys) As Short
    End Function
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        '' Code By LeftSpace
    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        If GetAsyncKeyState(Keys.LButton) <> 0 Then '' Sol Mouse tuşu basılıysa
            Dim aPencere As IntPtr = GetForegroundWindow() '' aktif pencereyi alıyoruz
            Dim aProcOut As Integer = Nothing  '' processid değişkenimiz
            GetWindowThreadProcessId(aPencere, aProcOut) '' burada pencere hwnd ile processid öğreniyoruz

            If aProcOut Then '' processid var ise textbox texte aktarıyoruz
                TextBox1.Text = aProcOut.ToString()
                '' olası hata yakalama
                Try
                    '' veya direk GetProcessById İlede olabilir
                    For Each tmp As Process In Process.GetProcesses()
                        If tmp.Id = aProcOut Then
                            TextBox2.Text = tmp.ProcessName
                        End If
                    Next
                    '' GetProcessByID örneği

                    TextBox2.Text = Process.GetProcessById(aProcOut).ProcessName
                Catch ex As Exception

                End Try
            End If
        End If
    End Sub
End Class