I am working on the application (C# 2.0). I have implemented single instance in it. Everything is fine. If i run the application again, it shows messagebox saying "instance is already running".
Actually i don't want to show the message through messagebox.
I want to show this message using Balloon tip of already running instance (it has notify icon in system tray).
How can i achieve this?
Thanks in advance.
You need a form of interprocess communication, to signal to the other instance that it should display the messagebox.
In this instance, you could go one better than telling the existing instance to display the message, and instead tell it to restore it's main window (i.e. "unminimise").
You could use a WCF service inside you app.
Your second app connects to it via NetPipe, invode a method and closes.
Your first app receive the call and pops-up the baloon notification
The easiest way to implement a single instance and to inform the first one if a second is started is already implement in .Net. Just take a look into the following links:
The CodeFluent Runtime which is free set of tools provides a SingleInstance class to implement a single instance application:
You've just to override the WndProc method to pops-up your notification (Baloon tip).
来源：https://stackoverflow.com/questions/1255834/single-instance-and-notify-in-system-tray