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Preventing another instance in systray

Posted on 2000-04-05
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Last Modified: 2010-04-04
I have an app that resides in systray.  The common code I find for preventing another instance of my app works well when my app is on the taskbar but when in the systray, it forces a taskbar icon at the same time.  Maximizing the taskbar icon produces an invisible window and the systray icon is still present.  
I've been using Mutex Handles.  Is there a better way to do this?
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Question by:d32coder
3 Comments
 
LVL 13

Expert Comment

by:Epsylon
ID: 2688790
On this page you can see how to do that:

http://www.gnomehome.demon.nl/uddf/pages/api.htm#api0

Eps.
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LVL 20

Accepted Solution

by:
Madshi earned 75 total points
ID: 2688807
I'm using this:

  if (CreateMutex(nil, false, 'd32codersTrayApp') = 0) or (GetLastError = ERROR_ALREADY_EXISTS) then
  ExitProcess(0);

You should add this as the first line of your project (dpr) like this:

begin
  if (CreateMutex...
  Application.Initialize;
  Application...
  ...
end.

Regards, Madshi.
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Author Comment

by:d32coder
ID: 2701805
Love it.  Works great and with only one line of code.  Thanks!
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