C# Application 하나만 실행되게.

[DllImport("user32.dll")] 

[return: MarshalAs(UnmanagedType.Bool)] 

static extern bool SetForegroundWindow(IntPtr hWnd); 

/// <summary> 

/// The main entry point for the application. 

/// </summary> 

[STAThread] 

static void Main() 

{ 

bool createdNew = true; 

using (Mutex mutex = new Mutex(true, "MyApplicationName", out createdNew)) 

{ 

if (createdNew) 

{ 

Application.EnableVisualStyles(); 

Application.SetCompatibleTextRenderingDefault(false); 

Application.Run(new MainForm()); 

} 

else 

        { 

Process current = Process.GetCurrentProcess(); 

foreach (Process process in Process.GetProcessesByName(current.ProcessName)) 

{ 

if (process.Id != current.Id) 

{ 

SetForegroundWindow(process.MainWindowHandle); 

break; 

} 

} 

} 

} 

}