This question might seem a bit vague but here we go.
I am preventing multiple instances of my wpf application, like so:
Process proc = Process.GetCurrentProcess();
if (Process.GetProcessesByName(proc.ProcessName).Length > 1)
{
Application.Current.Shutdown();
return;
}
if (e.Args != null && e.Args.Count() > 0)
{
this.Properties["Magnet"] = e.Args;
}
Is it possible to pass the command-line arguments to the application already running?
No, it is not possible. You should use some of inter process communication techniques.