xy-coordinates to lParam

[Quix]

Hi,

how can I convert xy-coordinates to the lParam-value used in PostMessage?
It must be something like lParam = y*&HFFFF+x, but this doesn't work.

PostMessage hwnd, WM_LBUTTONDOWN, 1, lParam

thanks,
Quix

[jim mcnamara]

Pass the lParam as a PointAPI UDT.

'        code fragment  WILL NOT WORK....

Public Type POINTAPI
    x As Long
    y As Long
End Type

.........................
Dim MyThing as PointAPI
SendMessage hWnd, WM_WHATEVER, VarPtr(MyThing)...............

[Quix]

Thanks for your reply, but it doesn't work
I was using this code:

Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Const WM_LBUTTONDOWN = &H201
Private Const WM_LBUTTONUP = &H202
Private Type POINTAPI
        x As Long
        y As Long
End Type

Private Sub Command1_Click()
Dim lpPoint As POINTAPI
lpPoint.x = 100
lpPoint.y = 40
PostMessage Me.hwnd, WM_LBUTTONDOWN, 1, VarPtr(lpPoint)
PostMessage Me.hwnd, WM_LBUTTONUP, 0, VarPtr(lpPoint)
End Sub

But then the coordiantes are sent as follows:
xPos:-2804, yPos:18 (see MS-Spy++)

Btw does anybody know what is the wParam for?

[Quix]

It works!

Private Sub Command1_Click()
Dim lParam As Long, _
x As Long, y As Long
x = 10
y = 80
lParam = y * 65535 + x + y
PostMessage Me.hwnd, WM_LBUTTONDOWN, 1, lParam
PostMessage Me.hwnd, WM_LBUTTONUP, 0, lParam
End Sub

But why do I have to add the y-value both to the LOWORD and HIWORD of lParam?

[faisalkm]

Whats this 65535?

[Quix]

65535 is the hex-value &HFFFF.
It's to create a DWORD of the LOWORD and HIWORD-values.

Finally I'm using this code:

lParam = (y * &H10000) Or (x And &HFFFF&)

[faisalkm]

by the way it's not working for me!!!!!

[Quix]

What is not working?
Try this:

Public Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
 
Public Const WM_LBUTTONDOWN = &H201, _
WM_LBUTTONUP = &H202
 
Sub MouseClick(hwnd as Long, x as Long, y as Long)
  lParam = (y * &H10000) Or (x And &HFFFF&)
  PostMessage hwnd, WM_LBUTTONDOWN, 1, lParam
  PostMessage hwnd, WM_LBUTTONUP, 0, lParam
End Sub

This code simulates a mouseclick on the window with the handle hwnd at the position x,y.