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From: garyusenet on 20 Dec 2006 09:47
I dont really understand the difference between FindWindow and
FindWindowEx, i'm new to all of this - so it's quite confusing.

Gary-

garyusenet(a)myway.com wrote:

> Dustin thankyou, I have queried the return value of my SetWindowPos and
> it is returning false when I run it first time, and True when I cancel
> my program, comment out the launchapp, and rerun the program. So it's
> the SetWindowPos that's failing first time around.
>
> I'll look into spy++ that you mentioned now, and see if it sheds any
> light on why this is.
>
> Many Thanks,
>
> Gary-
>
> Dustin Campbell wrote:
>
> > > The original (originalapp.exe) ran in fullscreen. Somebody wrote a
> > > programme app.exe which runs originalapp.exe in a window. This is the
> > > reason why I have to use FindWindow to find the Hwnd of
> > > originalapp.exe
> > > from within app.exe and can't just query the process p for it's Hwnd.
> > > Thanks very much for comments,
> >
> > Why not improve your search by using FindWindowEx so that you can narrow
> > your search to the children of Process.MainWindowHandle?
> >
> > Best Regards,
> > Dustin Campbell
> > Developer Express Inc.

From: Dustin Campbell on 20 Dec 2006 09:55
> Dustin thankyou, I have queried the return value of my SetWindowPos
> and it is returning false when I run it first time, and True when I
> cancel my program, comment out the launchapp, and rerun the program.
> So it's the SetWindowPos that's failing first time around.
>
> I'll look into spy++ that you mentioned now, and see if it sheds any
> light on why this is.

Is the handle returned by FindWindow (and being passed into SetWindowPos)
valid?

Best Regards,
Dustin Campbell
Developer Express Inc.


From: Dustin Campbell on 20 Dec 2006 10:00
> For this first time today I used the System.Diagnositcs namespace to
> launch a program from my c# code. The program launches OK but I have
> something which has completely stumped me.
>
> The SetWindowPos method does not work. If I run the code as it is
> presented below, app.exe launches in its own window and is displayed
> at the top left part of the screen. However it isn't repositioned
> which is what the last piece of code should do. HOWEVER if i end my c#
> program and leave app.exe open - and then comment out the launchapp()
> part of Form1_load and just run my c# program again the window is
> moved as expected. So for some reason the SetWindowPos method is only
> working if app.exe is open BEFORE I run my c# code, and not when I use
> my C# code to open app.exe. Any ideas why this is please?

Is it possible that the problem is because your "launchapp" code makes the
window hidden?

Best Regards,
Dustin Campbell
Developer Express Inc.


From: Dustin Campbell on 20 Dec 2006 10:02
> I dont really understand the difference between FindWindow and
> FindWindowEx, i'm new to all of this - so it's quite confusing.

FindWindowEx allows you to specify a few extra parameters to narrow your
search. If the window that your searching for is parented by another window
(as you said in your original post), you should be able to use FindWindowEx
to locate that window and pass the Process.MainWindowHandle as the parent
window. Here's how I define both APIs in C#:

[DllImport("user32.dll")]
static extern IntPtr FindWindow([MarshalAs(UnmanagedType.LPTStr)] string
lpClassName, [MarshalAs(UnmanagedType.LPTStr)] string lpWindowName);

[DllImport("user32.dll")]
static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter,
[MarshalAs(UnmanagedType.LPTStr)] string lpszClass, [MarshalAs(UnmanagedType.LPTStr)]
string lpszWindow);

Using the code that you original posted (untested!!):

private Process launchapp()
{
Process p = new Process();
p.StartInfo.FileName = @"C:\Program Files\app\directory\app.exe";
p.StartInfo.WorkingDirectory = @"C:\Program Files\app\directory\";
p.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
p.Start();
return p;
}

private void Form1_Load(object sender, EventArgs e)
{
launchapp();

// window handle, place window at top of Z order, WP left, WP top, width,
height
int handle = FindWindowEx(p.MainWindowHandle, IntPtr.Zero, null, "Title
of Application Window");
SetWindowPos((IntPtr)handle, (IntPtr)HWND_TOP, 5, 5, 5, 5,0);
}

Best Regards,
Dustin Campbell
Developer Express Inc.


From: garyusenet on 20 Dec 2006 11:36
After much investigation and armed with your kind advice Dustin I have
found the problem.

There is a delay between the launch of app.exe and the availability of
the Hwnd that i'm searching for.

I have managed to overcome this by using the following: -

while (handle == 0)
{
handle = FindWindow(null, "title of application");
}

//here i make the calls to the api's only once my hwnd has a value that
isn't 0.

The only problem with this is it causes a fairly significant delay
between the time of launching my c# code, and the app.exe actually
being launched. (Which surprised me because my P.Start() is actually
BEFORE the while code i have placed above.

Any ideas why this delay may be happening and how i might overcome it?

Thanks,

Gary-

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