Mono Basics

After you get Mono installed, it's probably a good idea to run a quick Hello World program to make sure everything is setup properly. This allows you to know that your Mono is working before you try writing or running a more complex application.

Console Hello World

To test the most basic functionality available, copy the following code into a file called hello.cs. 

using System;
 
public class HelloWorld
{
	static public void Main ()
	{
		Console.WriteLine ("Hello Mono World");
	}
 
}

To compile, use mcs: 

mcs hello.cs

Using mcs to compile produces a .Net 1.1 assembly. To create a .Net 2.0 assembly, use gmcs: 

gmcs hello.cs

Either compiler will create "hello.exe", which you can run using: 

mono hello.exe

The program should run and output: 

Hello Mono World

Gtk# Hello World

The following program tests writing a Gtk# application. 

using Gtk;
using System;
 
class Hello {
 
        static void Main()
        {
                Application.Init ();
 
                Window window = new Window ("helloworld");
                window.Show();
    
                Application.Run ();
    
        }
}

To compile, use mcs as well as the -pkg command to tell the compiler to pull in the Gtk# libraries: 

mcs hello.cs -pkg:gtk-sharp-2.0

Using mcs to compile produces a .Net 1.1 assembly. To create a .Net 2.0 assembly, use gmcs: 

gmcs hello.cs -pkg:gtk-sharp-2.0

Either compiler will create "hello.exe", which you can run using: 

mono hello.exe

Winforms Hello World

The following program tests writing a Winforms application. 

using System;
using System.Windows.Forms;
 
public class HelloWorld : Form
{
	static public void Main ()
	{
		Application.Run (new HelloWorld ());
	}
 
	public HelloWorld ()
	{
		Text = "Hello Mono World";
	}
}

To compile, use mcs as well as the -pkg command to tell the compiler to pull in the Winforms libraries: 

mcs hello.cs -pkg:dotnet

Using mcs to compile produces a .Net 1.1 assembly. To create a .Net 2.0 assembly, use gmcs: 

gmcs hello.cs -pkg:dotnet

Either compiler will create "hello.exe", which you can run using: 

mono hello.exe

ASP.Net Hello World

Create a text file with the extension .aspx and put on it: 

<%@ Page Language="C#" %>
<html>
<head>
   <title>Sample Calendar</title>
</head>
<asp:calendar showtitle="true" runat="server">
</asp:calendar>

Then run the xsp command from that directory: 

$ xsp

Use a web browser to contact http://localhost:8080/filename.aspx