When using "assembly.getexecutingassembly().getcustomattributes(typeof(guidattribute), false).getvalue(0)).value" in C #, an "index was outside the bounds of the array" error occurs

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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

in

Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(0)).Value.ToString()

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,
Reza Jaferi

What I have tried:

C#

public MainWindow()
{
    //class GlobalMutex
    InitializeComponent();
    GlobalMutex GM = new GlobalMutex();
    GM.SingleGlobalInstance();
}

Posted 30-Aug-22 10:55am

Reza jafery

Updated 31-Aug-22 1:27am

v4

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2 solutions

Solution 1

Simple: GetCustomAttributes is returning an empty collection, so your attempt to get the zeroth element is failing.
Use the debugger to find out why for your app, we can't run your code under exactly the same circumstances you can.

Posted 30-Aug-22 11:04am

OriginalGriff

Comments

Reza jafery 30-Aug-22 17:10pm

Thanks for the answer. I know that this collection is empty, but why?

OriginalGriff 30-Aug-22 17:39pm

"Use the debugger to find out why for your app, we can't run your code under exactly the same circumstances you can."

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Dave Kreskowiak · Accepted Answer · 2022-08-30T15:27:00

Solution 2

C#

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

What is going to hinder your debugging, and therefore make your code unsupportable, is that you're chaining (cramming) all these method and property calls in a single statement. NEVER DO THIS!! It makes your code difficult to debug since you cannot see the intermediate return values being passed down the chain and cannot see where the problem occurs.

As for why the code is failing, does your app even have a GUID? Open the Properties node of your project in Solution Explorer, click on the Application tab, then on the "Assembly Information..." button. In the dialog that appears, is the GUID field filled in with a VALID guid? For example: 69D69F94-225B-4B31-B149-04E8A1183D05

Posted 30-Aug-22 15:27pm

Dave Kreskowiak

Updated 30-Aug-22 15:29pm

v2

Comments

Reza jafery 31-Aug-22 7:16am

"What is going to hinder your debugging, ... " It is useful for debugging the app, but once it has been debugged and completed, I prefer to code as shown above (chained) because the fewer variables defined, the less RAM is required.

Dave Kreskowiak 31-Aug-22 9:49am

You're not really saving RAM with that technique. Once the code is compiled in Release, optimizations will take care of the RAM. Besides, nobody cares about, what, 16 bytes, you think you're going to save.

Reza jafery 31-Aug-22 10:42am

Although 16 bytes may appear to be a small amount, when we have a large design with a large number of variables, after debugging we can save a few megabytes by using this approach instead of GC.Collect.

Dave Kreskowiak 31-Aug-22 10:44am

Seriously, you're not really saving anything. The compilers optimizer is already doing it for you.

Chances are really high, if you're calling GC.Collect, you're doing something wrong.

Reza jafery 31-Aug-22 10:55am

I know that the compiler actually performs this, however, let's say you have a project where 200 variables are momentarily used and then terminated after the application finishes. In such cases, this approach would also be helpful.

Dave Kreskowiak 31-Aug-22 10:59am

Uhhh... no it wouldn't. It doesn't matter how many variables you're using. When appropriate, the compiler will optimize the chain in for you. (and if you're using 200 variables at once in a method, you're REALLY doing something wrong)

You are literally making your debugging/support life more difficult for no reason at all! You, and your crew, would probably greatly benefit from reading a book on compiler theory.

Reza jafery 31-Aug-22 12:44pm

I use this approach when I'm done coding and debugging.

Reza jafery 31-Aug-22 12:45pm

The best is yet to come.I use the following facilities as much as possible:1. for loop instead of foreach in sequential operations,2. Parallel.For loop instead of for loop,3. Choosing the best Collections for insertion and deletion,4. switch statement instead of if else and if,5. Accurate choice of variable type,6. I try to use more design languages for design so as not to do it dynamically in C#,7. Unsubscribing from event subscriptions to avoid memory leaks if the event is defined with += event is defined with +=,8. Fastest concatenation of multiple strings in sequence StringBuilder, String.Join and etc,9. Utilization of the Skip(i).Take() method if possible in the for loop,10. Using Database Indexes, 11. Reduce Data Redundancy, And ...

Dave Kreskowiak 31-Aug-22 13:05pm

...and? It that list has nothing to do with the conversation at hand.

Dave Kreskowiak 31-Aug-22 13:04pm

I keep saying it because you don't have to do it. When the compiler gets to the broken out code, it will figure out that it can chain those calls together, as appropriate. You THINK you're saving the space, but you're not. The compiler is way ahead of you, as is probably even optimizing the code even more than you think you're doing it.

Reza jafery 31-Aug-22 13:29pm

We assume that my technique has no effect on optimization, but the complexity of the code makes the app unreadable, making it more difficult for someone to hack it and therefore increasing the code's security.

Dave Kreskowiak 31-Aug-22 13:35pm

BWHAHAHAA! I neve said your technique has no impact on optimization. I said your technique is pointless because the compiler is optimizing it for you. You can write it as you already have, or you can write it as separate statements. It doesn't matter to the compiler. It will optimize the code either way and generate the same IL code.

You think how you wrote the code increases the security of it? No, it doesn't. Not even close. You want to see? Open your existing code in ILDASM and look for the generated for that statement. You're not hiding anything from anyone.All you're doing is making your debugging experience more difficult. You can leave the code written as separate statements and the compiler is smart enough to see what you're doing and optimize the chain in for you if you compile using a Release configuration. The compiler is really good at managing memory and register use, something you THINK you're doing yourself, but you're not.

Reza jafery 31-Aug-22 13:35pm

In general, I appreciate your advice.

Reza jafery 31-Aug-22 7:16am

As for why the code is failing, does your app even have a GUID? ... You are exactly right; my app's "AssemblyInfo.cs" needed the following code:

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

Dave Kreskowiak 31-Aug-22 9:52am

I'm not changing anything and you're not going to delete the comment. I described how to get to the value you needed to make sure exists for your code to work.

Going through the Properties/Application Info dialog adds that line of code for you.

When using "assembly.getexecutingassembly().getcustomattributes(typeof(guidattribute), false).getvalue(0)).value" in C #, an "index was outside the bounds of the array" error occurs

2 solutions

Solution 2

Solution 1

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When using "assembly.getexecutingassembly().getcustomattributes(typeof(guidattribute), false).getvalue(0)).value" in C #, an "index was outside the bounds of the array" error occurs

2 solutions

Solution 2

Solution 1

Add your solution here

Preview 0

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