[vb2008] Press the button of an external not foreground / minimized window

[phil2000]

known the external window size, it Hwnd and the x/y coordinates of the button to press, I am trying this code, like seen on the web:

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

    Const WM_LBUTTONDOWN As UInteger = &H201

    'button X coordinates, tried both X => respect to it window coordinates
    'and X respect to Screen coordinates (when the window is not minimized)
    Dim X as Integer = ....     

    'button Y coordinates, tried both Y => respect to it window coordinates 
    'and Y respect to Screen coordinates (when the window is not minimized)
    Dim Y as Integer = ....   
 
    Dim Hwnd as IntPtr = ...   ' external window handle

    PostMessage(Hwnd, WM_LBUTTONDOWN, IntPtr.Zero, MakeLParam(X, Y))


    Private Function MakeLParam(ByVal LoWord As Integer, ByVal HiWord As Integer) As IntPtr

        Return New IntPtr((HiWord << 16) Or (LoWord And &HFFFF))

    End Function

but nothing happens, both if the external window is in foreground, NOT in foreground or minimized...

what's wrong?

ty

[Edgemeal]

If you know the handle of the button you might want to try...

    Private Declare Function PostMessage Lib "user32.dll" Alias "PostMessageA" (ByVal hwnd As Integer, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
    Private Const BM_CLICK As Integer = &HF5

'
'
    Dim ButnHwnd as Integer = ...   ' external button handle
    PostMessage(ButnHwnd, BM_CLICK, 0, 0)

[phil2000]

unfortunately I don't know the handle of the button and I can't know it: it's not a standard Windows button....

[Edgemeal]

unfortunately I don't know the handle of the button and I can't know it: it's not a standard Windows button....

One problem might be sending IntPtr.Zero as the mouse button param, shouldn't that be 1 for a left mouse button? Also you would most likely send a WM_LBUTTONUP after sending the WM_LBUTTONDOWN message.

I don't have time to test in .NET so I just did this in VB6 real quick to send a mouse up & down message to a VB10 apps picturebox, it worked even when the VB10 app was minimized.
' <<<< VB6 code >>>>>>

Dim Butn As Long
Dim DaWord As Long
Dim rc As RECT

'Butn = ... ' handle of the VB10 app pic box.
If Butn <> 0 Then
    GetWindowRect Butn, rc ' get cords. 
    DaWord = MakeDWord((rc.Right - rc.Left) / 2, (rc.Bottom - rc.Top) / 2) ' center
    PostMessage Butn, WM_LBUTTONDOWN, 1&, DaWord
    PostMessage Butn, WM_LBUTTONUP, 1&, DaWord
End If

Private Function MakeDWord(ByVal LoWord As Integer, ByVal HiWord As Integer) As Long
    MakeDWord = (HiWord * &H10000) Or (LoWord And &HFFFF&)
End Function

EDIT
BTW, I noticed when the the VB10 app was minimized the pic box didn't fire a Click event, only the mouse Down and Up events fired, so making it work will depend how your external apps control is coded, if the control detects key presses then sending WM_KEYDOWN/UP messages might work better?

FWIW, my attempt to convert the VB6 to VB10 code, it works in my test but not sure if it is correctly coded.

Public Class Form1
    Const WM_LBUTTONDOWN As Int32 = &H201
    Const WM_LBUTTONUP As Int32 = &H202

    Structure RECT
        Public Left As Int32
        Public Top As Int32
        Public Right As Int32
        Public Bottom As Int32
    End Structure

    Declare Function GetWindowRect Lib "user32.dll" (ByVal hwnd As Int32, ByRef lpRect As RECT) As Int32
    Declare Function PostMessage Lib "user32.dll" Alias "PostMessageA" (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam As Int32, ByVal lParam As Int32) As Int32

    Private Function MakeDWord(ByVal LoWord As Int32, ByVal HiWord As Int32) As Int32
        MakeDWord = (HiWord * &H10000) Or (LoWord And &HFFFF)
    End Function

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Butn, DaWord As Int32
        Dim rc As RECT

        ' handle of the control to send messages to
        Butn = 0 ' <<< change to the controls handle.

        If Butn Then
            ' cords of control
            GetWindowRect(Butn, rc)
            ' center of control
            DaWord = MakeDWord((rc.Right - rc.Left) / 2, (rc.Bottom - rc.Top) / 2)
            ' messages to control
            PostMessage(Butn, WM_LBUTTONDOWN, 1, DaWord)
            PostMessage(Butn, WM_LBUTTONUP, 1, DaWord)
        End If
    End Sub

End Class

[phil2000]

ty for the reply... nothing to do...

replacing IntPtr.Zero with Ctype(1,IntPtr) and adding the WM_LBUTTONUP code nothing changes

at this point may be the better way should be to find the handle of the button... but if I look with Spy++ I can see that in the window there are 8 buttons all with the same ClassName and all without Caption... *** can Spy++ find the handles of 8 different buttons with Same Class Name and without Caption text?????

EDIT

no way!!

I have got the button handle by Spy++ (hex 00010822) and tried:

PostMessage(67618, BM_CLICK, 0, 0)

but it don't works.... damn Poker Room user defined buttons!