Preventing another instance in systray

Posted on 2000-04-05
Medium Priority
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?
Question by:d32coder
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
LVL 13

Expert Comment

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


LVL 20

Accepted Solution

Madshi earned 300 total points
ID: 2688807
I'm using this:

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

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

  if (CreateMutex...

Regards, Madshi.

Author Comment

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

Featured Post

New benefit for Premium Members - Upgrade now!

Ready to get started with anonymous questions today? It's easy! Learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
In my programming career I have only very rarely run into situations where operator overloading would be of any use in my work.  Normally those situations involved math with either overly large numbers (hundreds of thousands of digits or accuracy re…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…
Want to learn how to record your desktop screen without having to use an outside camera. Click on this video and learn how to use the cool google extension called "Screencastify"! Step 1: Open a new google tab Step 2: Go to the left hand upper corn…
Suggested Courses

718 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question