Why MainWindowHandl e is zero?

Luke

Question: why Process.MainWin dowHandle is zero?

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From document of Process.MainWin dowHandle Property:

Property Value
The system-generated window handle of the main window of the associated
process.
Exceptions
Exception TypeCondition
InvalidOperatio nExceptionThe MainWindowHandl e is not defined because the
process has exited.
NotSupportedExc eptionYou are attempting to retrieve the MainWindowHandl e for
a process that is running on a remote computer.

Remarks
You can get the MainWindowHandl e property only for processes that are
running on the local computer. The MainWindowHandl e property is a value that
uniquely identifies the window that is associated with the process.
A process has a main window associated with it only if the process has a
graphical interface. If the associated process does not have a main window,
the MainWindowHandl e value is zero. If you have just started a process and
want to use its main window handle, consider using the WaitForInputIdl e
method to allow the process to finish starting, ensuring that the main
window handle has been created. Otherwise, an exception will be thrown.
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I am trying to use GetProcessesByN ame("xxxx.exe") and then get the main
window's handle via Process.MainWin dowHandle; however, the return value is
zero.
1) the process is not in a remote computer;
2) the code works well if I change the process name to another one; e.g.
winmine.exe (the small game: mine sweeper :) )
3) the process xxxx.exe has finished starting. It is a kind of media player
and starts very fast. In fact, to testify that it has a main window handle,
I have tried to use Spy++ to find it and get its main window's handle and
title normally. Then I call SendMessage(hWn d, WM_GETTEXT, xxx, xxx) and get
its title.

1) Why I can NOT get the main window's handle via Process.MainWin dowHandle?
2) What you will do to accomplish this? I am trying EnumWindows()

Any response is highly appreciated. Thanks

Jul 21 '05 #1

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