Ошибка компилятора cs5001

If you want to create an executable file from your ‘C#’ project or file, your code should contain a ‘static Main’ method. This is an entry point to ‘C#’ program. Otherwise, ‘C#’ compiler will throw the below error:

error CS5001: Program 'xyz.exe' does not contain a static 'Main' method suitable for an entry point

To resolve this error, we have two options here.

• One is, add ‘static Main‘ method into the project or the class.
  • Entry point for standalone ‘C#’ application is it’s ‘Main’ method. ‘static Main‘ method should exist in any one class in ‘C#’ project or file.
• Other option is, build the project or file as a library (DLL – Dynamic Link Library).
  • These type of files are not self-executable. DLL files will be used into other assemblies or applications. So, for these file, ‘Main’ entry point is not required.

That said, depending on the requirement, we can create a self executable file or a DLL from the ‘C#’ code file or project.

Let’s take a simple example to produce the error and discuss about the steps to resolve the issue.

// Sample.cs
public class Sample
{
    public void Display()
    {
        System.Console.WriteLine("Hello, World!");
    }
};

When we compile above program; ‘C#’ compiler will throw below error:

c:>csc Sample.cs
Microsoft (R) Visual C# Compiler version 4.0.30319.17929
for Microsoft (R) .NET Framework 4.5
Copyright (C) Microsoft Corporation. All rights reserved.

error CS5001: Program 'c:Sample.exe'
        does not contain a static 'Main' method suitable for an entry point

As we mentioned above, we have two ways to resolve this problem. Lets try to resolve this without modifying any code.

Compile the above program “Sample.cs” as a target library instead of an executable. Below is the command:

c:>csc /target:library Sample.cs
Microsoft (R) Visual C# Compiler version 4.0.30319.17929
for Microsoft (R) .NET Framework 4.5
Copyright (C) Microsoft Corporation. All rights reserved.

Observe that 'C#' compiler successfully compiled the program and generates "Sample.dll" file.

Another way to resolve this error is, by adding the ‘static Main’ method. ‘Main’ method should be added into the ‘Sample’ class as a static method. After adding the ‘Main’ method above code looks like below.

// Sample.cs
public class Sample
{
    public void Display()
    {
        System.Console.WriteLine("Hello, World!");
    }

    static void Main()
    {
    }
};

Now compile this program and observe that ‘C#’ compiler successfully compiled the program and generates “Sample.exe” file. Below is the command to compile above code:

csc basic.cs

We can choose any one of these methods, depending on our requirements, to resolve this issue “error CS5001”.

(Raju)

Csc error cs5001 program

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I added yesterday a class and added some code from a website. Later on I want it to remove it from the solution so what I did is started VS and remove it from the solution. Since then I received this error when I want to start and test the Windows Form Application.

So what I did is Google around but I found nothing what results into the solution. I checked every form for in any case something that’s looks like a Main. So what I found on the top in every form was:

public (form name)()
<
InitializeComponent();
>

I’m afraid that I’ve done something wrong, but I don’t know what. So the title is what I see when the program itself is starting to build it. The error list says: Program does not contain a static ‘Main’ method suitable for an entry point. I see only a red cross. No error code. But the file is CSC, so what is that?

So I was hoping that someone could help me so that I could test/build the solution again. Thanks anyway!

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Compiler Error CS5001

Program does not contain a static ‘Main’ method suitable for an entry point

This error occurs when no static Main method with a correct signature is found in the code that produces an executable file. It also occurs if the entry point function, Main , is defined with the wrong case, such as lower-case main . For information about the rules that apply to the Main method, see Main() and Command-Line Arguments.

If the Main method has an async modifier, make sure that the selected C# language version is 7.1 or higher and to use Task or Task as the return type.

The Main method is only required when compiling an executable file, that is, when the exe or winexe element of the TargetType compiler option is specified. The following Visual Studio project types specify one of these options by default:

• Console application
• ASP.NET Core application
• WPF application
• Windows Forms application

The following example generates CS5001:

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Источник

Csc error cs5001 program

This forum has migrated to Microsoft Q&A. Visit Microsoft Q&A to post new questions.

Answered by:

Question

I added yesterday a class and added some code from a website. Later on I want it to remove it from the solution so what I did is started VS and remove it from the solution. Since then I received this error when I want to start and test the Windows Form Application.

So what I did is Google around but I found nothing what results into the solution. I checked every form for in any case something that’s looks like a Main. So what I found on the top in every form was:

public (form name)()
<
InitializeComponent();
>

I’m afraid that I’ve done something wrong, but I don’t know what. So the title is what I see when the program itself is starting to build it. The error list says: Program does not contain a static ‘Main’ method suitable for an entry point. I see only a red cross. No error code. But the file is CSC, so what is that?

So I was hoping that someone could help me so that I could test/build the solution again. Thanks anyway!

Источник

Csc error cs5001 program

This forum has migrated to Microsoft Q&A. Visit Microsoft Q&A to post new questions.

Answered by:

Question

>
catch (Exception e)
<
Console.WriteLine(e.ToString());
>
>
public static int Main(String[] inc)
<
// String[] inc = Environment.GetCommandLineArgs();
string incomm = new string(inc);
int found = incomm.IndexOf(«comm=», System.StringComparison.CurrentCultureIgnoreCase);
if (found

Answers

Please note that language specification requires Main() «should not be public», so you have to remove the keyword there.

• Edited by cheong00 Editor Monday, February 27, 2017 2:33 AM
• Proposed as answer by Kristin Xie Tuesday, February 28, 2017 3:31 AM
• Marked as answer by Gaurav Aroraa Wednesday, March 8, 2017 4:20 PM

I’ve tested your code, why it builds no error CS5001_Program on my side? Only char array issue.

And this error means When you start a program, the computer needs to know where to actually start running code, that’s what the Main() method is for. It is required to run, and that’s the error you are receiving.

MSDN Community Support
Please remember to click «Mark as Answer» the responses that resolved your issue, and to click «Unmark as Answer» if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

Thank you Kristin and Wayne, it works fine now.

here is the code:

Please note that language specification requires Main() «should not be public», so you have to remove the keyword there.

• Edited by cheong00 Editor Monday, February 27, 2017 2:33 AM
• Proposed as answer by Kristin Xie Tuesday, February 28, 2017 3:31 AM
• Marked as answer by Gaurav Aroraa Wednesday, March 8, 2017 4:20 PM

<
// String[] inc = Environment.GetCommandLineArgs();
string incomm = new string(inc);

why I get this error code?

Probably because you got build errors from the compile. Look at the Output
from the Build and fix any errors before trying to proceed.

P.S. — Note that inc is an array.

I’ve tested your code, why it builds no error CS5001_Program on my side? Only char array issue.

And this error means When you start a program, the computer needs to know where to actually start running code, that’s what the Main() method is for. It is required to run, and that’s the error you are receiving.

MSDN Community Support
Please remember to click «Mark as Answer» the responses that resolved your issue, and to click «Unmark as Answer» if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

I am sorry it doesn’t work, please look at the compilation output:

1>—— Build started: Project: zcmd, Configuration: Debug Any CPU ——
1>CSC : error CS5001: Program does not contain a static ‘Main’ method suitable for an entry point
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

and the code now is:

>
catch (Exception e)
<
Console.WriteLine(e.ToString());
>
>
static int Main(String[] inc)
<
// String[] inc = Environment.GetCommandLineArgs();
string incomm = new string(inc);
int found = incomm.IndexOf(«comm=»,System.StringComparison.CurrentCultureIgnoreCase);
if (found

Could you show your screen capture here? Or could you recreate an new console application then paste these codes and build again? Please try and tell me your result here.

MSDN Community Support
Please remember to click «Mark as Answer» the responses that resolved your issue, and to click «Unmark as Answer» if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

I am sorry it doesn’t work, please look at the compilation output:

1>—— Build started: Project: zcmd, Configuration: Debug Any CPU ——
1>CSC : error CS5001: Program does not contain a static ‘Main’ method suitable for an entry point
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

and the code now is:

static int Main(String[] inc)

<
// String[] inc = Environment.GetCommandLineArgs();
string incomm = new string(inc);

I don’t think the code you are posting here is what is actually in the
project you’re building. If it were, you would get errors from this line:

string incomm = new string(inc);

Those errors would have to be fixed before the build would ever reach the
point of issuing the CS5001 error about the Main function. So what is
being built with your project is *not* the code you’re showing us. Even if
that is the code you are working on in the IDE editor.

Источник

C# – How to fix “error CS5001: Program ‘xyz.exe’ does not contain a static ‘Main’ method suitable for an entry point”?

If you want to create an executable file from your ‘C#’ project or file, your code should contain a ‘static Main’ method. This is an entry point to ‘C#’ program. Otherwise, ‘C#’ compiler will throw the below error:

To resolve this error, we have two options here.

• One is, add ‘ static Main ‘ method into the project or the class.
  • Entry point for standalone ‘C#’ application is it’s ‘Main’ method. ‘ static Main ‘ method should exist in any one class in ‘C#’ project or file.
• Other option is, build the project or file as a library (DLL – Dynamic Link Library).
  • These type of files are not self-executable. DLL files will be used into other assemblies or applications. So, for these file, ‘Main’ entry point is not required.

That said, depending on the requirement, we can create a self executable file or a DLL from the ‘C#’ code file or project.

Let’s take a simple example to produce the error and discuss about the steps to resolve the issue.

When we compile above program; ‘C#’ compiler will throw below error:

As we mentioned above, we have two ways to resolve this problem. Lets try to resolve this without modifying any code.

Compile the above program “Sample.cs” as a target library instead of an executable. Below is the command:

Another way to resolve this error is, by adding the ‘static Main’ method. ‘Main’ method should be added into the ‘Sample’ class as a static method. After adding the ‘Main’ method above code looks like below.

Now compile this program and observe that ‘C#’ compiler successfully compiled the program and generates “Sample.exe” file. Below is the command to compile above code:

We can choose any one of these methods, depending on our requirements, to resolve this issue “error CS5001”.

Источник

I have created a Microsoft .Net Core 2.1 Console App. This is my code

using System;
using Microsoft.Azure.EventHubs;
using System.Threading.Tasks;
using System.Threading;
using System.Text;
using System.Collections.Generic;

namespace bog_cs_AzureIoTMessageReader
{
    class Program
    {
        private readonly static string s_eventHubsCompatibleEndpoint = "sb://foobar.servicebus.windows.net/";
        private readonly static string s_eventHubsCompatiblePath = "...";
        private readonly static string s_iotHubSasKey = "secret";
        private readonly static string s_iotHubSasKeyName = "secret";
        private static EventHubClient s_eventHubClient;

        private static async Task ReceiveMessagesFromDeviceAsync(string partition, CancellationToken ct)
        {
            // Create the receiver using the default consumer group.
            // For the purposes of this sample, read only messages sent since 
            // the time the receiver is created. Typically, you don't want to skip any messages.
            var eventHubReceiver = s_eventHubClient.CreateReceiver("$Default", partition, EventPosition.FromEnqueuedTime(DateTime.Now));
            Console.WriteLine("Create receiver on partition: " + partition);
            while (true)
            {
                if (ct.IsCancellationRequested) break;
                Console.WriteLine("Listening for messages on: " + partition);
                // Check for EventData - this methods times out if there is nothing to retrieve.
                var events = await eventHubReceiver.ReceiveAsync(100);

                // If there is data in the batch, process it.
                if (events == null) continue;

                foreach (EventData eventData in events)
                {
                    string data = Encoding.UTF8.GetString(eventData.Body.Array);
                    Console.WriteLine("Message received on partition {0}:", partition);
                    Console.WriteLine("  {0}:", data);
                    Console.WriteLine("Application properties (set by device):");
                    foreach (var prop in eventData.Properties)
                    {
                        Console.WriteLine("  {0}: {1}", prop.Key, prop.Value);
                    }
                    Console.WriteLine("System properties (set by IoT Hub):");
                    foreach (var prop in eventData.SystemProperties)
                    {
                        Console.WriteLine("  {0}: {1}", prop.Key, prop.Value);
                    }
                }
            }
        }


        static async Task Main(string[] args)
        {
            Console.WriteLine("IoT Hub Quickstarts - Read device to cloud messages. Ctrl-C to exit.n");

            // Create an EventHubClient instance to connect to the
            // IoT Hub Event Hubs-compatible endpoint.
            var connectionString = new EventHubsConnectionStringBuilder(new Uri(s_eventHubsCompatibleEndpoint), s_eventHubsCompatiblePath, s_iotHubSasKeyName, s_iotHubSasKey);
            s_eventHubClient = EventHubClient.CreateFromConnectionString(connectionString.ToString());

            // Create a PartitionReciever for each partition on the hub.
            var runtimeInfo = await s_eventHubClient.GetRuntimeInformationAsync();
            var d2cPartitions = runtimeInfo.PartitionIds;

            CancellationTokenSource cts = new CancellationTokenSource();

            Console.CancelKeyPress += (s, e) =>
            {
                e.Cancel = true;
                cts.Cancel();
                Console.WriteLine("Exiting...");
            };

            var tasks = new List<Task>();
            foreach (string partition in d2cPartitions)
            {
                tasks.Add(ReceiveMessagesFromDeviceAsync(partition, cts.Token));
            }

            // Wait for all the PartitionReceivers to finsih.
            Task.WaitAll(tasks.ToArray());

        }
    }
}

When i execute this, i receive the error

1>—— Build started: Project: bog-cs-AzureIoTMessageReader,
Configuration: Debug Any CPU —— 1>Program.cs(55,22,55,26): error
CS8107: Feature ‘async main’ is not available in C# 7.0. Please use
language version 7.1 or greater. 1>CSC : error CS5001: Program does
not contain a static ‘Main’ method suitable for an entry point 1>Done
building project «bog-cs-AzureIoTMessageReader.csproj» — FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Whats wrong here? How can i fix this?

I have created a Microsoft .Net Core 2.1 Console App. This is my code

using System;
using Microsoft.Azure.EventHubs;
using System.Threading.Tasks;
using System.Threading;
using System.Text;
using System.Collections.Generic;

namespace bog_cs_AzureIoTMessageReader
{
    class Program
    {
        private readonly static string s_eventHubsCompatibleEndpoint = "sb://foobar.servicebus.windows.net/";
        private readonly static string s_eventHubsCompatiblePath = "...";
        private readonly static string s_iotHubSasKey = "secret";
        private readonly static string s_iotHubSasKeyName = "secret";
        private static EventHubClient s_eventHubClient;

        private static async Task ReceiveMessagesFromDeviceAsync(string partition, CancellationToken ct)
        {
            // Create the receiver using the default consumer group.
            // For the purposes of this sample, read only messages sent since 
            // the time the receiver is created. Typically, you don't want to skip any messages.
            var eventHubReceiver = s_eventHubClient.CreateReceiver("$Default", partition, EventPosition.FromEnqueuedTime(DateTime.Now));
            Console.WriteLine("Create receiver on partition: " + partition);
            while (true)
            {
                if (ct.IsCancellationRequested) break;
                Console.WriteLine("Listening for messages on: " + partition);
                // Check for EventData - this methods times out if there is nothing to retrieve.
                var events = await eventHubReceiver.ReceiveAsync(100);

                // If there is data in the batch, process it.
                if (events == null) continue;

                foreach (EventData eventData in events)
                {
                    string data = Encoding.UTF8.GetString(eventData.Body.Array);
                    Console.WriteLine("Message received on partition {0}:", partition);
                    Console.WriteLine("  {0}:", data);
                    Console.WriteLine("Application properties (set by device):");
                    foreach (var prop in eventData.Properties)
                    {
                        Console.WriteLine("  {0}: {1}", prop.Key, prop.Value);
                    }
                    Console.WriteLine("System properties (set by IoT Hub):");
                    foreach (var prop in eventData.SystemProperties)
                    {
                        Console.WriteLine("  {0}: {1}", prop.Key, prop.Value);
                    }
                }
            }
        }


        static async Task Main(string[] args)
        {
            Console.WriteLine("IoT Hub Quickstarts - Read device to cloud messages. Ctrl-C to exit.n");

            // Create an EventHubClient instance to connect to the
            // IoT Hub Event Hubs-compatible endpoint.
            var connectionString = new EventHubsConnectionStringBuilder(new Uri(s_eventHubsCompatibleEndpoint), s_eventHubsCompatiblePath, s_iotHubSasKeyName, s_iotHubSasKey);
            s_eventHubClient = EventHubClient.CreateFromConnectionString(connectionString.ToString());

            // Create a PartitionReciever for each partition on the hub.
            var runtimeInfo = await s_eventHubClient.GetRuntimeInformationAsync();
            var d2cPartitions = runtimeInfo.PartitionIds;

            CancellationTokenSource cts = new CancellationTokenSource();

            Console.CancelKeyPress += (s, e) =>
            {
                e.Cancel = true;
                cts.Cancel();
                Console.WriteLine("Exiting...");
            };

            var tasks = new List<Task>();
            foreach (string partition in d2cPartitions)
            {
                tasks.Add(ReceiveMessagesFromDeviceAsync(partition, cts.Token));
            }

            // Wait for all the PartitionReceivers to finsih.
            Task.WaitAll(tasks.ToArray());

        }
    }
}

When i execute this, i receive the error

1>—— Build started: Project: bog-cs-AzureIoTMessageReader,
Configuration: Debug Any CPU —— 1>Program.cs(55,22,55,26): error
CS8107: Feature ‘async main’ is not available in C# 7.0. Please use
language version 7.1 or greater. 1>CSC : error CS5001: Program does
not contain a static ‘Main’ method suitable for an entry point 1>Done
building project «bog-cs-AzureIoTMessageReader.csproj» — FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Whats wrong here? How can i fix this?