When using "Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(0)).Value" in C#, an "Index was outside the bounds of the array" error occurs

Question

To run a single instance of a program, I use the following approach, which is recommended in this link rather than the approach presented here.

C#:

using System;  
using System.Reflection;  
using System.Runtime.InteropServices;  
using System.Security.AccessControl;  
using System.Security.Principal;  
using System.Threading;  
using System.Windows;  
  
namespace My_App  
{  
    /// <summary>  
    /// Interaction logic for App.xaml  
    /// </summary>  
    static class GlobalMutex  
    {  
        public static void SingleGlobalInstance()  
        {  
            string AppGuid = ((GuidAttribute)Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(0)).Value.ToString();  
            string MutexId = string.Format("Global\\{{{0}}}", AppGuid);  
            bool CreatedNew;  
            var AllowEveryoneRule = new MutexAccessRule(new SecurityIdentifier(WellKnownSidType.WorldSid, null), MutexRights.FullControl, AccessControlType.Allow);  
            var SecuritySettings = new MutexSecurity();  
            SecuritySettings.AddAccessRule(AllowEveryoneRule);  
            using (var mutex = new Mutex(false, MutexId, out CreatedNew, SecuritySettings))  
            {  
                var HasHandle = false;  
                try  
                {  
                    try  
                    {  
                        HasHandle = mutex.WaitOne(5000, false);  
                        switch (HasHandle)  
                        {  
                            case false:  
                                throw new TimeoutException("Timeout waiting for exclusive access");  
                        }  
  
                    }  
                    catch (AbandonedMutexException)  
                    {  
                        HasHandle = true;  
                    }  
                }  
                finally  
                {  
                    switch (HasHandle)  
                    {  
                        case true:  
                            mutex.ReleaseMutex();  
                            break;  
                    }  
                }  
            }  
        }  
    }  
  
    public partial class App : Application  
    {  
        protected override void OnStartup(StartupEventArgs e)  
        {  
            GlobalMutex.SingleGlobalInstance();  
            base.OnStartup(e);  
        }  
    }  
}  

But I get the following error:

Index was outside the bounds of the array

at line 5.

What is the cause of this error and how can it be resolved?
I use the following tools:

• NET Framework 4.5
• WPF

Thank you for your time.
Best regards

Answer 1

Try adding this line:

[assembly: Guid( "F6341D4D-5A4D-429F-B587-28CD958B27F2" )]

to any source file, outside of classes and namespaces (or to AssemblyInfo.cs file if your project contains it).

Answer 2

Hi @Reza Jaferi ,

string AppGuid = ((GuidAttribute)Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(0)).Value.ToString();

This code is for get application GUID as defined in AssemblyInfo.cs.

It could not be obtained in debug mode.

Please try to debug in release mode.

Best Regards,
Jiale

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