Checking if Application is already running

[cpope]

I am trying to make sure only one instance of my application is running at one time. This code does not work. The Length is always 0. Does anyone know how to accomplish this task?

if(System.Diagnostics.Process.GetProcessesByName(System.Diagnostics.Process.GetCurrentProcess().ProcessName).Length > 1)
{
MessageBox.Show("Message Board Is Already Running","Message Board",MessageBoxButtons.OK,MessageBoxIcon.Asterisk);
this.Close();
}

 

[minhhoa]

I see it runs OK when I put them in the main entry point of the application and instead of "this.Close" I use "return".

 

[cpope]

I am still having trouble, the app still thinks there are 0 processes of the name running and allows me to open multiple instances of the application... here is the new code:

[STAThread]
static void Main()
{
Int32 runningProcesses = Process.GetProcessesByName(Process.GetCurrentProcess().ProcessName).Length;
MessageBox.Show(Process.GetCurrentProcess().ProcessName +" "+ runningProcesses);

if(System.Diagnostics.Process.GetProcessesByName(System.Diagnostics.Process.GetCurrentProcess().ProcessName).Length > 0)
{
MessageBox.Show("Message Board Is Already Running","Message Board",MessageBoxButtons.OK,MessageBoxIcon.Asterisk);
return;
}
else
{
Application.Run(new ClientWindow());
}
}

 

[cpope]

*** FOUND A SOLUTION *****
Here is code that I found worked for my application:


static void Main()
{
Mutex currapp = new Mutex(false,&quot;<MessageBoardMutex>&quot;
if(!currapp.WaitOne(0,false))
{
MessageBox.Show(&quot;Message Board Is Already Running&quot;,&quot;Message Board&quot;,MessageBoxButtons.OK,MessageBoxIcon.Asterisk);
return;
}
else
Application.Run(new ClientWindow());
}