PostMessage does not work in CF

  • Thread starter Thread starter mottebelke
  • Start date Start date
M

mottebelke

I want to use PostMessage to send a WM_LBUTTONUP message to a control
to simulate the clicking on that control.
The problem I have is that the function always returns an error: 87 -
Invalid parameter. This is even the case when I change the message to
WM_CLOSE for example.
I can't see where I went wrong.

[DllImport("coredll.dll")]
public static extern bool PostMessage
(
IntPtr hWnd, // handle to destination window
Int32 Msg, // message
Int32 wParam, // first message parameter
Int32 lParam // second message parameter
);

----

IntPtr hwnd=0;
if (storeObsButton != null)
{
// get hwnd of control
storeObsButton.Capture = true;
hwnd = GetCapture();
storeObsButton.Capture = false;
}

bool lngResult;
if (hwnd != IntPtr.Zero)
{
lngResult = PostMessage(hwnd, WM_LBUTTONUP, 0, 0);
}

----
 
Have you considered using the built-in
Microsoft.WindowsCE.Forms.MessageWindow.PostMessage method?

Also check your defined windows message constants, and check your hwnd is
valid.

Peter
 
Yes, I tried the managed PostMessage, but that gave me the same result.
I checked the message constants as well, and they look fine:

public const Int32 WM_LBUTTONDOWN = 0x0201;
public const Int32 WM_LBUTTONUP = 0x0202;
 
Ilya said:
I'd say by the way of exclusion we can assume hWnd is not valid.
Click to expand...

Well, then why does SendMessage work with the exact same handle and
message constants?

And no, I can't use SendMessage, because in some scenarios the button
click handler waits on other input which I have to enter
programmatically as well.


I'll have another look at mouse_event tomorrow, but I gave that a try
already today with no luck.
 
Daniel said:
mouse_event example here:
http://www.danielmoth.com/Blog/2004/11/mouseevent.html

If you are still having troubles with your PostMessage why not post a full
repro.

Cheers
Daniel
Click to expand...

I tried your example, but it still doesn't work.

Something I didn't mention yet, and which might be the problem cause is
that I want to click a button in another application than where I'm
running the PostMessage/mouse_event from.
I use Reflection to start the 'external' application and then use the
GetMethod, GetProperty and Invoke functions to control it (get the
handles, find the controls, etc.).

Does PostMessage/mouse_event work when you're trying it on a different
application started with reflection?
 
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