Ошибка cs8802 только одна единица компиляции может содержать инструкции верхнего уровня

I just started learning c#, I created C# console application. To understand the concepts, I watched videos of how to setup vs code for c#

When I run the dotnet new console command in VS code terminal, it creates a new project including Program.cs file.

In the video, the Program.cs file appears like that

// Program.cs
using System;
namespace HelloWorld
{
  class Program
  {
    static string Main(string[] args)
    {
      Console.WriteLine("Hello, World!");
    }
  }
}

Program.cs in my IDE appears like,

// Program.cs
// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");

When I run the code using terminal dotnet run it runs perfectly on my computer.

when I create a new cs file, it contains

// hello.cs
Console.WriteLine("hello world");

after running it says Only one compilation unit can have top-level statements.

when I use class method and namespace like

// hello.cs
namespace helloworld
{
    class hello
    {
        static void Main()
        {
            Console.WriteLine("hello world");

        }
    }
}

it runs THE Program.cs file not the new file and shows this warning

PS C:UsersUserC#projects> dotnet run hello.cs C:UsersUserC#projectshello.cs(5,21): warning CS7022: The entry point of the program is global code; ignoring 'hello.Main()' entry point. [C:UsersUserC#projectsC#projects.csproj] Hello, World!

Project structure:

I tried another method by pressing run and debug and show nothing.

When I click on Generate c# Assets for Build and Debug button it shows this

Could not locate .NET Core project. Assets were not generated.

I just started learning c#, I created C# console application. To understand the concepts, I watched videos of how to setup vs code for c#

When I run the dotnet new console command in VS code terminal, it creates a new project including Program.cs file.

In the video, the Program.cs file appears like that

// Program.cs
using System;
namespace HelloWorld
{
  class Program
  {
    static string Main(string[] args)
    {
      Console.WriteLine("Hello, World!");
    }
  }
}

Program.cs in my IDE appears like,

// Program.cs
// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");

When I run the code using terminal dotnet run it runs perfectly on my computer.

when I create a new cs file, it contains

// hello.cs
Console.WriteLine("hello world");

after running it says Only one compilation unit can have top-level statements.

when I use class method and namespace like

// hello.cs
namespace helloworld
{
    class hello
    {
        static void Main()
        {
            Console.WriteLine("hello world");

        }
    }
}

it runs THE Program.cs file not the new file and shows this warning

PS C:UsersUserC#projects> dotnet run hello.cs C:UsersUserC#projectshello.cs(5,21): warning CS7022: The entry point of the program is global code; ignoring 'hello.Main()' entry point. [C:UsersUserC#projectsC#projects.csproj] Hello, World!

Project structure:

I tried another method by pressing run and debug and show nothing.

When I click on Generate c# Assets for Build and Debug button it shows this

Could not locate .NET Core project. Assets were not generated.

В dotnet 6 для основного метода не требуется имя класса.

Поэтому, когда у вас есть 2 класса, у которых нет класса и пространства имен, компилятор думает, что у вас есть 2 основных метода.

Итак, вы делаете что-то вроде

namespace ConsoleApp1;

class Program1
{
    public static void GetRolling()
    {
        Random numberGen = new Random();

        int roll1 = 1;
        int roll2 = 0;
        int roll3 = 0;
        int roll4 = 0;

        int attempts = 0;

        Console.WriteLine("Press enter to roll the dies");

        while (roll1 != roll2 || roll2 != roll3 || roll3 != roll4 || roll4 != roll1)
        {
            Console.ReadKey();

            roll1 = numberGen.Next(1, 7);
            roll2 = numberGen.Next(1, 7);
            roll3 = numberGen.Next(1, 7);
            roll4 = numberGen.Next(1, 7);
            Console.WriteLine("Dice 1: " + roll1 + "nDice 2: " + roll2 + "nDice 3: " + roll3 + "nDice 4: " + roll4 + "n");
            attempts++;
        }

        Console.WriteLine("It took " + attempts + " attempts to roll a four of a kind.");
    }
}

А для программы2 некоторые думают так:

namespace ConsoleApp1;

public class Program2
{
    public static void Main(string[] args)
    {
        Program1.GetRolling();
        Console.ReadKey();
    }
}

В противном случае это все равно, что сказать 2 раза public static void Main(string[] args), а это невозможно.

// Program.cs
using System;
namespace HelloWorld
{
  class Program
  {
    static string Main(string[] args)
    {
      Console.WriteLine("Hello, World!");
    }
  }
}

// Program.cs
// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");

// hello.cs
Console.WriteLine("hello world");

// hello.cs
namespace helloworld
{
    class hello
    {
        static void Main()
        {
            Console.WriteLine("hello world");

        }
    }
}

1 ответ

Лучший ответ

namespace helloworld
{
    class hello
    {
        static void Main()
        {
            Console.WriteLine("hello world");  
        }
    }
}

Console.WriteLine("hello world");