Now you can't run two copies of app accidentally

1 files changed, 29 insertions, 3 deletions

diff --git a/Program.cs b/Program.cs
index bda5dee7..d25745a6 100644
--- a/Program.cs
+++ b/Program.cs
@@ -1,21 +1,47 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
+using System.Runtime.InteropServices;
+using System.Threading;
 using System.Windows.Forms;
 
 namespace com.clusterrr.hakchi_gui
 {
     static class Program
     {
+        [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()
         {
-            Application.EnableVisualStyles();
-            Application.SetCompatibleTextRenderingDefault(false);
-            Application.Run(new MainForm());
+            bool createdNew = true;
+            using (Mutex mutex = new Mutex(true, "hakchi2", 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;
+                        }
+                    }
+                }
+            }
         }
     }
 }