ubuntu 24.04 C# install no2

ubuntu 24.04 C# install no2

第１

Mono Basics | Mono

第２
HTTPS connections
To make sure HTTPS connections work, run the following command to check whether you can connect to nuget.org:

csharp -e 'new System.Net.WebClient ().DownloadString ("https://www.nuget.org")'
The program prints the website contents if everything works or throws an exception if it doesn’t.

第３
using System;
using System.Windows.Forms;

public class HelloWorld : Form
{
static public void Main ()
{
Application.Run (new HelloWorld ());
}

public HelloWorld ()
{
    Text = "Hello Mono World";
}

}
csc hello.cs -r:System.Windows.Forms.dll

error 発生
原因わからず

以上