.NET inter-process "events"

Question

I have multiple instances of the same application running. The user ask can click "Quit" on each instance to shut it down.

I would like to add the choice to "Quit All Instances", which will raise some kid of "event" that notifies all instances of the application that they should close. I don't need to transport any data along with this event.

What's the best (and preferably simplest) way to do this in Windows using C#/.NET?

Answer 1

Send the good'ol WM_CLOSE to all instances...

Process[] processes = Process.GetProcesses();
string thisProcess = Process.GetCurrentProcess().MainModule.FileName;
string thisProcessName = Process.GetCurrentProcess().ProcessName;
foreach (Process process in processes)
{
   // Compare process name, this will weed out most processes
   if (thisProcessName.CompareTo(process.ProcessName) != 0) continue;
   // Check the file name of the processes main module
   if (thisProcess.CompareTo(process.MainModule.FileName) != 0) continue;
   if (Process.GetCurrentProcess().Id == process.Id) 
   {
     // We don't want to commit suicide
     continue;
   }
   // Tell the other instance to die
   Win32.SendMessage(process.MainWindowHandle, Win32.WM_CLOSE, 0, 0);
}

Answer 2

The System.Diagnostics.Process class has several methods you can use.

Process.GetProcessesByName will let you enumerate all instances:

http://msdn.microsoft.com/en-us/library/system.diagnostics.process.getprocessesbyname.aspx

then Process.CloseMainWindow or Process.Close will shut them down:

http://msdn.microsoft.com/en-us/library/system.diagnostics.process.closemainwindow.aspx http://msdn.microsoft.com/en-us/library/system.diagnostics.process.close.aspx