CODEWITHSUNDEEP
c#visual-studio-2010
atwellpub
atwellpub

Reputation: 6010

Does not contain a static 'main' method suitable for an entry point

I began organizing my code to day into seperarate .cs files, and in order to allow the methods that work with the UI to continue to do so I would create the .cs code under the same namespace and public partial class name so the methods could be inter-operable.

My header look like this in four files, including my main core file that calls: 

public shell()
{
InitializeComponent(); 
}

Header area of .cs files that work with the UI (and seem to be causing this new conflict):

using System;
using System.Windows.Forms;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.IO;
using System.Data.SqlServerCe;
using System.Diagnostics;
using System.Threading;
using System.Collections.Specialized;
using System.Net;
using System.Runtime.InteropServices;
using watin = WatiN.Core;
using WatiN.Core.Native.InternetExplorer;
using System.Web; 


namespace WindowsFormsApplication1
{

    public partial class shell : Form
    {

Now when I try to debug/preview my application (BTW this is a Windows Application within Visual Studio 2010 Express) I get this error message:

Does not contain a static 'main' method suitable for an entry point

I looked in the application properties in Application->Startup object, but it offers me no options. How can I inform the application to begin at the .cs file that has my InitializeComponent(); command?

I'm still very new and this is my first attempt at an organizing method with c# code.

Upvotes: 140

Views: 477306

Answers (30)

Lê Hồng Thái
Lê Hồng Thái

Reputation: 1

My Solutions:

  • Remove configuration in .csproj file. Remove: <OutputType>Exe</OutputType>

enter image description here

  • Add Main() endpoint

There are 2 mainly reasons for this error:

  1. Configurations in .csproj file makes the .NET project will be built into .exe / .dll file ( by run dotnet build). Incase, we config the .csproj with option: Exe the .NET project will be built to .exe file that need an Main() endpoint. So that why the error happening.

  2. Don't have Main() endpoint

Upvotes: 0

Markus
Markus

Reputation: 1211

I had the public static void Main( string[] args ) which I had changed to public async static void Main( string[] args ) and back again to public static void Main( string[] args ).

The error went away after a Rebuild All.

Upvotes: 0

Krishan Kanoria
Krishan Kanoria

Reputation: 1

There can be another cause of this issue - if you have cloned your repo and the cloned URL is something like this - Demovsts.visualstudio.com/Demo.com/_git/Demo%20AI%20Site

Here repository name should be like this - Demo-AI-Site but not with spaces.

Sometimes due to the space in the repo name(Demo%20AI%20Site), it could not able to clone properly and when we build and run the application we see the error.

Upvotes: 0

heisendolf
heisendolf

Reputation: 1

For me none of the answers really helped without tampering with my Project in any way.

But what worked (after checking every possible cause of the error and trying out every solution) was... simply restarting VS2022 and opening again xd.

Upvotes: 0

Gaurang Naik
Gaurang Naik

Reputation: 253

Make sure you are not using void with async like

static async void Main(string[] args)

If yes, then change void to Task like

static async Task Main(string[] args)

Upvotes: 24

Ishara Samintha
Ishara Samintha

Reputation: 530

Add

static async Task Main(string[] args)
{
}

instead of

static async void Main(string[] args)
{
}

its work for me.

Upvotes: 2

Ogglas
Ogglas

Reputation: 69958

I got this error when using the command Build Docker Image in Visual Studio 2022.

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

The project built perfectly well in Windows but I tried to build a Linuxcontainer. Switching to Output Type Class Library solved the error but Docker Compose gave me this error instead:

CTC1031 Linux containers are not supported for

https://stackoverflow.com/a/74044317/3850405

I tried explicitly using a Main method like this but it did not work:

namespace WebApplication
{
    public class Program
    {
        public static void Main(string[] args)
        {

I have no idea why but this solved it for me:

Gives error:

FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /src
COPY ["src/Services/Classification/ClassificationService.Api/ClassificationService.Api.csproj", "Services/Classification/ClassificationService.Api/"]

RUN dotnet restore "Services/Classification/ClassificationService.Api/ClassificationService.Api.csproj"
COPY . .
WORKDIR "/src/Services/Classification/ClassificationService.Api"
RUN dotnet build "ClassificationService.Api.csproj" -c Release -o /app/build

Works:

FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /src
COPY ["src/Services/Classification/ClassificationService.Api/ClassificationService.Api.csproj", "src/Services/Classification/ClassificationService.Api/"]

RUN dotnet restore "src/Services/Classification/ClassificationService.Api/ClassificationService.Api.csproj"
COPY . .
WORKDIR "/src/src/Services/Classification/ClassificationService.Api"
RUN dotnet build "ClassificationService.Api.csproj" -c Release -o /app/build

Notice the double /src in the working example.

I read that you had to place the Dockerfile at the same level as .sln file but in my case the files are separated by four levels.

https://stackoverflow.com/a/63257667/3850405

Upvotes: 1

Hakan Bayazit
Hakan Bayazit

Reputation: 438

Did you accidentally remove the entire Program.cs file? If you have removed,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace ListWievKullanımı
{
   static class Program
   {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

This might work for you.

enter image description here

Upvotes: 1

Siddhi Kamat
Siddhi Kamat

Reputation: 155

After placing the above code in Program.cs, follow below steps

  1. Right click on the project

  2. Select Properties

  3. Set Output Type to Windows Application

  4. Startup object : namepace.Program

Upvotes: 2

Elseif
Elseif

Reputation: 11

If you use Visual Studio Code change Project Sdk="Microsoft.NET.Sdk.Web" to Project Sdk="Microsoft.NET.Sdk" on csproj file.

Upvotes: 1

smoksnes
smoksnes

Reputation: 10851

Another situation where this occur is when someone (unintentionally) changes Build Action for Program.cs. The value for Build Action should be C# compiler.

I accidentally changed Build Action to None, which removed program.cs from the project and therefore wasn't included when compile started.

Upvotes: 1

Ata Hoseini
Ata Hoseini

Reputation: 137

enter image description here

Just right click on project and select properties and then set Output type on Class Library

Upvotes: 4

ririvas
ririvas

Reputation: 11

Perhaps unintentional, but moving my docker file to the solution folder instead of the project eliminated the error. This was helpful when I still wanted to run the solution independently of docker

Upvotes: -1

Ali Ahmadi
Ali Ahmadi

Reputation: 670

I had this error and solved it using this solution.

  1. Right click on the project
  2. Select "Properties"
  3. Set "Output Type" to "Class Library".

Upvotes: 50

Jan
Jan

Reputation: 2249

Had this problem in VS 2017 caused by:

static async Task Main(string[] args)

(Feature 'async main' is not available in C# 7.0. Please use language version 7.1 or greater)

Adding

<LangVersion>latest</LangVersion>

to app.csproj helped.

Upvotes: 12

bereket gebredingle
bereket gebredingle

Reputation: 12996

Edit .csproj file

<OutputType>Library</OutputType>

cheers !

Upvotes: 20

Moondog 2112
Moondog 2112

Reputation: 71

For me, the error was actually produced by "Feature 'async main' is not available in C# 7.0. Please use language version 7.1 or greater". This issue was resulting in the "Does not contain a static 'main' method suitable for an entry point" message in the Error List, but the Output window showed the "not available" error. To correct this, I changed the language version from 'C# latest minor version (default)' to 'C# latest minor version (latest)' under Advanced Build Settings.

Upvotes: 6

Ali Jamal
Ali Jamal

Reputation: 1559

Salaam, I have both Visual Studio 2017 and Visual Studio 2019

Visual Studio 2019 does not show this error but 2017 does. Try Installing Visual Studio 2019.

Visual Studio 2017

Visual Studio 2017 

Visual Studio 2019

Visual Studio 2019

Upvotes: 2

Manveer Singh
Manveer Singh

Reputation: 357

If you are using a class library project then set Class Library as output type in properties under application section of project.

Upvotes: 2

Peter Kindberg
Peter Kindberg

Reputation: 21

A valid entry looks like:

public static class ConsoleProgram
    {
        [STAThread]
        static void Main()
        {
            Console.WriteLine("Got here");
            Console.ReadLine();
        }
    }

I had issues as I'm writing a web application, but for the dreadly loading time, I wanted to quickly convert the same project to a console application and perform quick method tests without loading the entire solution.

My entry point was placed in /App_Code/Main.cs, and I had to do the following:

  1. Set Project -> Properties -> Application -> Output type = Console Application
  2. Create the /App_Code/Main.cs
  3. Add the code above in it (and reference the methods in my project)
  4. Right click on the Main.cs file -> Properties -> Build Action = Compile

After this, I can set the output (as mentioned in Step 1) to Class Library to start the web site, or Console Application to enter the console mode.

Why I did this instead of 2 separate projects?

Simply because I had references to Entity Framework and other specific references that created problems running 2 separate projects.

For easier solutions, I would still recommend 2 separate projects as the console output is mainly test code and you probably don't want to risk that going out in production code.

Upvotes: 1

yash patel
yash patel

Reputation: 19

hellow your main class was deleted so add new class that name set as Main.cs and pest that code or if porblem in window so same problem on that

using System;
using System.Collections.Generic;
using System.Linq;
using Foundation;
using UIKit;

namespace your_PKG_name.iOS
{
       public class Application
        {
            // This is the main entry point of the application.
            static void Main(string[] args)
            {
                // if you want to use a different Application Delegate class from "AppDelegate"
                // you can specify it here.
                UIApplication.Main(args, null, "AppDelegate");

            }
        }
}

Upvotes: 1

Madison Haynie
Madison Haynie

Reputation: 488

For some others coming here:

In my case I had copied a .csproj from a sample project which included <EnableDefaultCompileItems>false</EnableDefaultCompileItems> without including the Program.cs file. Fix was to either remove EnableDefaultCompileItems or include Program.cs in the compile explicitly

Upvotes: 1

Adam Cox
Adam Cox

Reputation: 3661

If you are like me, then you might have started with a Class Library, and then switched this to a Console Application. If so, change this...

namespace ClassLibrary1
{
    public class Class1
    {
    }
}

To this...

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
        }
    }
}

Upvotes: 0

Gerrie Pretorius
Gerrie Pretorius

Reputation: 4131

When you want to allow paramaters to be specified from the command, they must look like this:

 [STAThread]
 static void Main(params string[] paramaters)
 {

you cannot specify more than one paramater, otherwise this will also cause the error reported above.

Upvotes: 2

James Wierzba
James Wierzba

Reputation: 17498

Check to see if the project is set as the "Startup Project"

Right click on the project and choose "Set as Startup Project" from the menu.

Upvotes: 0

grumpy
grumpy

Reputation: 31

For future readers who faced same issue with Windows Forms Application, one solution is to add these lines to your main/start up form class:

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new MyMainForm());
    }

Then go to project properties > Application > Startup Object dropdown, should see the namespace.MyMainForm, select it, clean and build the solution. And it should work.

Upvotes: 0

MaChaToc
MaChaToc

Reputation: 139

I am using Visual Studio and also had this problem. It took me some time, but in my program it was caused because I accidentally deleted a Class named "Program" that is generated automatically.

Upvotes: 0

Roman Volkov
Roman Volkov

Reputation: 390

  1. Select App.xaml and display its properties. Set Build Action to ApplicationDefinition.
  2. App.xaml and its corresponding *.cs file must be placed into the root directory of the *.csproj file, i. e. not into a "Source" folder.

Upvotes: 14

Prasad
Prasad

Reputation: 956

I too have faced this problem. Then I realized that I was choosing Console Application(Package) rather than Console Application.

Upvotes: 0

simonbs
simonbs

Reputation: 8042

If you do have a Main method but still get this error, make sure that the file containing the Main method has "Build action" set to "Compile" and "Copy to ouput directory" set to "Do not copy".

Upvotes: 8

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