Possible Duplicate:
What is the correct way to create a single instance application?
How can I check if my application is already open? If my application is already running, I want to show it instead of opening a new instance.
[DllImport("user32.dll")]
private static extern Boolean ShowWindow(IntPtr hWnd, Int32 nCmdShow);
static void Main()
{
Process currentProcess = Process.GetCurrentProcess();
var runningProcess = (from process in Process.GetProcesses()
where
process.Id != currentProcess.Id &&
process.ProcessName.Equals(
currentProcess.ProcessName,
StringComparison.Ordinal)
select process).FirstOrDefault();
if (runningProcess != null)
{
ShowWindow(runningProcess.MainWindowHandle, SW_SHOWMAXIMIZED);
return;
}
}
Method 2
static void Main()
{
string procName = Process.GetCurrentProcess().ProcessName;
// get the list of all processes by the "procName"
Process[] processes=Process.GetProcessesByName(procName);
if (processes.Length > 1)
{
MessageBox.Show(procName + " already running");
return;
}
else
{
// Application.Run(...);
}
}