Imports System.Runtime.InteropServices
Imports System.Threading
Imports System.Text

Public Class Form1

#Region "API Calls"
    <DllImport("user32.dll", SetLastError:=True)> _
    Private Shared Function GetForegroundWindow() As IntPtr
    End Function

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
    End Function

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function SetWindowText(ByVal hwnd As IntPtr, ByVal lpString As String) As Boolean
    End Function

    Private Declare Function SendMessageByInt Lib "user32.dll" Alias "SendMessageA" _
      (ByVal hWnd As IntPtr, _
      ByVal uMsg As Int32, _
      ByVal wParam As Int32, _
      ByVal lParam As Int32) As Int32

    Private Declare Function SendMessageByString Lib "user32.dll" Alias "SendMessageA" _
         (ByVal hWnd As IntPtr, _
         ByVal uMsg As Int32, _
         ByVal wParam As Int32, _
         ByVal lParam As StringBuilder) As Int32

    Public Const WM_SETFOCUS As Int32 = &H7
    Public Const WM_GETTEXT As Int32 = &HD
    Public Const WM_GETTEXTLENGTH As Int32 = &HE
    Public Const WM_SETTEXT As Int32 = &HC
    Public Const WM_WINDOWPOSCHANGING As Int32 = &H46

    Private Shared Function GetText(ByVal hwnd As IntPtr) As String
        If (Not hwnd.Equals(IntPtr.Zero)) Then
            Dim length As Int32 = SendMessageByInt(hwnd, WM_GETTEXTLENGTH, 0, 0)

            If length > 0 Then
                Dim SB As New StringBuilder(length)
                Dim Result As Int32 = SendMessageByString(hwnd, WM_GETTEXT, length + 1, SB)

                If Result <> 0 Then
                    Return SB.ToString()
                Else
                    Return String.Empty
                End If
            Else
                Return String.Empty
            End If
        Else
            Return String.Empty
        End If
    End Function

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function GetWindowText(ByVal hwnd As IntPtr, ByVal lpString As StringBuilder, ByVal cch As Integer) As Integer
    End Function

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function GetWindowTextLength(ByVal hwnd As IntPtr) As Integer
    End Function

    Private Shared Function GetWindowTitle(ByVal hWnd As IntPtr) As String
        Dim length As Integer
        If hWnd.ToInt32 <= 0 Then
            Return ""
        End If
        length = GetWindowTextLength(hWnd)
        If length = 0 Then
            Return ""
        End If
        Dim sb As New System.Text.StringBuilder("", length + 1)

        GetWindowText(hWnd, sb, sb.Capacity)
        Return sb.ToString()
    End Function

    <StructLayout(LayoutKind.Sequential)> _
    Public Structure RECT
        Public left As Integer
        Public top As Integer
        Public right As Integer
        Public bottom As Integer
    End Structure

    <DllImport("user32.dll")> _
    Private Shared Function GetWindowRect(ByVal hWnd As IntPtr, ByRef rect As RECT) As IntPtr
    End Function

    <DllImport("user32.dll")> _
    Private Shared Function MoveWindow(ByVal hWnd As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal nWidth As Integer, ByVal nHeight As Integer, ByVal bRepaint As Boolean) As Boolean
    End Function
#End Region

#Region "Variables"
    Public IsRun As Boolean = False
    Public StoreLoadDialogRect As RECT
    Dim tWait As Thread
#End Region

#Region "Delegates"
    Delegate Sub StoreLoadRectDelegate(ByVal a As RECT)
    Public Sub StoreLoadRect(ByVal a As RECT)
        StoreLoadDialogRect = a
    End Sub

    Delegate Sub IsRunDelegate(ByVal a As Boolean)
    Public Sub IsRunSub(ByVal a As Boolean)
        IsRun = a
    End Sub

    Delegate Sub WriteTextDelegate(ByVal a As String)
    Public Sub WriteText(ByVal a As String)
        TextBox1.AppendText(a)
    End Sub
#End Region

#Region "Buttons"
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try
            tWait = New Thread(AddressOf WaitForDialog)
            tWait.Start(IsRun)
            If (OpenFileDialog1.ShowDialog) = DialogResult.OK Then
                TextBox1.AppendText(OpenFileDialog1.FileName.ToString & vbNewLine)
            End If
            If tWait.IsAlive Then
                tWait.Interrupt()
            End If
        Catch ex As Exception
        End Try
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Try
            tWait = New Thread(AddressOf WaitForDialog)
            tWait.Start(IsRun)
            If (OpenFileDialog2.ShowDialog) = DialogResult.OK Then
                TextBox1.AppendText(OpenFileDialog2.FileName.ToString & vbNewLine)
            End If
            If tWait.IsAlive Then
                tWait.Interrupt()
            End If
        Catch ex As Exception
        End Try
    End Sub
#End Region

#Region "Thread"
    Private Sub WaitForDialog(ByVal IsRun As Boolean)
        Try
            Dim rNew As RECT
            Dim rOld As RECT = StoreLoadDialogRect
            Dim hWnd As IntPtr = IntPtr.Zero
            Dim i As Integer = 0

            While hWnd.Equals(IntPtr.Zero) And i < 100
                Try
                    Threading.Thread.Sleep(100)
                    hWnd = GetForegroundWindow()
                    Dim act_hwnd_title As String = GetWindowTitle(hWnd)
                    If act_hwnd_title.Trim.ToLower.StartsWith("öffnen") Then
                        If IsRun Then
                            MoveWindow(hWnd, rOld.left, rOld.top, rOld.right - rOld.left, rOld.bottom - rOld.top, True)
                            Me.Invoke(New WriteTextDelegate(AddressOf WriteText), New Object() {"move " & rOld.left & " " & rOld.top & " " & rOld.right & " " & rOld.bottom & vbNewLine})
                        Else
                            Me.Invoke(New IsRunDelegate(AddressOf IsRunSub), New Object() {True})
                            GetWindowRect(hWnd, rNew)
                            Me.Invoke(New StoreLoadRectDelegate(AddressOf StoreLoadRect), New Object() {rNew})
                            Me.Invoke(New WriteTextDelegate(AddressOf WriteText), New Object() {"init " & rNew.left & " " & rNew.top & " " & rNew.right & " " & rNew.bottom & vbNewLine})
                        End If
                    Else
                        hWnd = IntPtr.Zero
                    End If
                Catch ex As Exception
                End Try
                i += 1
            End While
            While (Not hWnd.Equals(IntPtr.Zero))
                Try
                    Dim act_hwnd_title As String = GetWindowTitle(hWnd)
                    If act_hwnd_title = String.Empty Then
                        hWnd = IntPtr.Zero
                    Else
                        Me.Invoke(New IsRunDelegate(AddressOf IsRunSub), New Object() {True})
                        GetWindowRect(hWnd, rNew)
                        Me.Invoke(New StoreLoadRectDelegate(AddressOf StoreLoadRect), New Object() {rNew})
                        Me.Invoke(New WriteTextDelegate(AddressOf WriteText), New Object() {"new  " & rNew.left & " " & rNew.top & " " & rNew.right & " " & rNew.bottom & vbNewLine})
                    End If
                Catch ex As Exception
                End Try
                Threading.Thread.Sleep(50)
            End While
        Catch ex As ThreadInterruptedException
        End Try
    End Sub
#End Region

End Class