gistfile1.txt

Foo.csproj:

<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">

  <PropertyGroup>
    <OutputType>exe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <UseWindowsForms>true</UseWindowsForms>
  </PropertyGroup>

</Project>


Program.cs:
using System;
using System.Windows.Forms;

namespace tmp
{
    static class Program
    {
        /// <summary>
        ///  The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Console.WriteLine("Say something and it will be copied to the clipboard");

            var something = Console.ReadLine();

            Clipboard.SetText(something);

            Console.Read();
        }
    }
}