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In application A, I create a local COM server. And in COM server process, I

create a new process application B. The result is that application B is not

active application. I tried to set the parameter STARTINFO, but it did not

work. When I attached to the COM server process for debugging, the

application B become acitve application after creation. So I guess if some

work is done for COM server process by attaching to it. Any clue is

appreciated.


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"RobinZhou" wrote:



Is application A foreground application? If yes, then you

could try to call AllowSetForegroundWindow for process B

from it. Then process B would bring itself to foreground.

Read more about foreground and background windows here:



"Window Features"

msdn.microsoft.com/library/en-us/winui/winui/windowsuserinterface/windowing/windows/windowfeatures.asp">msdn.microsoft.com/library/en-us/winui/winui/windowsuserinterface/windowing/windows/windowfeatures.asp



See "Foreground and Background Windows" section.





HTH

Alex





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"Alex Blekhman" wrote:



not work.

BTW, the application B is C# application.

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RobinZhou wrote:

AllowSetForegroundWindow itsef is not enough. Process A

should call AllowSetForegroundWindow with process ID of B

process. Then process B should call SetForegroundWindow.

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"Alex Blekhman" wrote:



You mean I should use Enumwindow to enumerate windows in the COM server

process and set the window of application B as foreground window? it is a

hacking way, right? You know generally create a new process in one proces,

and the new process application is active. So I want to find the reason and

get a normal solution.

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RobinZhou wrote:

No, you should call AllowSetForegroundWindow in A process

with ID of B process. Then in B process (not COM server

process) call .NET equivalent of SetForegroundWindow to

bring main window of B process to foreground.



Process A just gives up its right to be foreground in favor

of process B. But process B still needs to do the work to

bring itself to foreground. However, if process A wasn't

foreground in first place, then it doesn't have the right to

be foreground, therefore it can't transfer this right to

other processes, as well. Read more about it in the MSDN

article by the link I posted earlier.

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"Alex Blekhman" wrote:



If I create a process for application B in application A directly not via

the local COM server process, application B is active. So I guess if it is

because of the local COM server is not a foreground process? Can we do some

work about it?

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RobinZhou wrote:

Hm.. I don't know how to make COM server to become

foreground process, since COM server usually doesn't have

any GUI at all. Probably you could call AttachThreadInput

from process A (after AllowSetForegroundWindow) to attach to

main window's thread of process B and then try to call

SetForegroundWindow. However, it looks like hack and I'm not

sure it will work reliably.

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"Alex Blekhman" wrote:



by SetPriorityClass(). But it is very weird that web MSDN has this priority

class but local MSDN does not have.

msdn.microsoft.com/wn3/aspx/postui.aspx&guid=&sloc=en-us&dg=microsoft.public.vc.language&base=msdn.microsoft.com/newsgroups/default.aspx&bclr=ececec&fclr=000000&sxml=msdn.microsoft.com/newsgroups/site.xml&stgxml=msdn.microsoft.com/newsgroups/settings.xml&sdgloc=en-US&tt=2">msdn.microsoft.com/wn3/aspx/postui.aspx&guid=&sloc=en-us&dg=microsoft.public.vc.language&base=msdn.microsoft.com/newsgroups/default.aspx&bclr=ececec&fclr=000000&sxml=msdn.microsoft.com/newsgroups/site.xml&stgxml=msdn.microsoft.com/newsgroups/settings.xml&sdgloc=en-US&tt=2

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"RobinZhou" wrote:



windowssdk.msdn.microsoft.com/en-us/library/ms686219(VS.80).aspx">windowssdk.msdn.microsoft.com/en-us/library/ms686219(VS.80).aspx

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RobinZhou wrote:

No, PROCESS_MODE_BACKGROUND_END is not related to GUI at

all. It just changes amount of CPU cycles granted to the

process.



This constant is relatively new, that's why your local MSDN

doesn't mention it.

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"Alex Blekhman" wrote:

I think you should pass ID of process B (and may be main

window's handle, too) to process A. Then from process A to

make process B as foreground.





HTH

Alex

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"Alex Blekhman" wrote:



want. communication between Process A and Process B is setup just by the

local COM server. So Process A cannot and should not communicate with process

B directly.

There is a weird thing that it works well on my machine with window 2003. I

don't know why. Is there any system info setting about it?

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"RobinZhou" wrote:



Process A doesn't need to communicate with B. It's enough

that COM server process will pass B's process ID back to A.

Also, you can try to create process B in suspended state,

then from process A, after it gave to B foreground rights,

resume process B. I never tried it myself, though.



I don't know why it works on Window 2003. Probably it has

different implementation of windows manager.





HTH

Alex





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