Using C# For Cross-Platform Development

sudo apt-get install mono-complete This command may also differ based on the environment, some may use yum, and some may use rpm or others. Please refer to your installer commands.

Wait, I cannot find the IDE. Where is it?

Correct, until now, you have only installed the binaries and assemblies required to make Mono workable. You have not yet installed the IDE. Until now you just installed the compilers and binaries. To install the IDE, execute the following command:

sudo apt-get install monodevelop

Now, head over to your IDE that was recently installed and start it! You are going to love it, and well, the folks have seriously put some great effort into it.

Ubuntu Studio shows the list of IDEs.

Hello World project opened in Mono Project.

In the next step, I will share a few examples of using C# to build cross-platform applications. Head over to the next step.

References

I am attaching a few good links in this section too,

• Visual Studio Community
• Mono Project — Official Website
• Install Mono

Building the applications

In this section, I will show you three sample codes for C#, which you already know in the .NET environment. The samples are not to give a new task in C#, but rather just a simple code, to help you understand how C# can be used to execute commands on different environments, different platforms, and so on.

Hello world from Linux

First of all, I want to make my application greet me, from a Linux environment, using the same code that you would use in a .NET environment. You all are already aware of the following code.

using System;
using System.Net.Http;

namespace HelloWorld
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Hello, who's there?");
            string name = "";
            name = Console.ReadLine();
            Console.WriteLine(string.Format("Hello {0} from Linux using C#.", name));
        }
    }
}

Aren’t you? Yes, it’s the same “elementary” C# code to greet someone! This time, running on a non-NET environment. This would just prompt me for some input and then continue to do what it was intended to do.

Pretty simple, right? But notice that this code now runs on a native Linux environment. There are no underground .NET frameworks supporting it. In reality, it is the Mono Runtime that does the processing underground. Please read the reference to Mono Runtime in the references below.

C# programming using collections

Collections are a great resource in any application, you can accept a long record of user data in a single object that is of type: Collection. C# has been providing generic programming objects, for collections. Collections are much better than arrays, because collections are mutable, unlike arrays. In this section, I will show you how to write an application that consumes the collections.

I created a class object, to hold the values of the people. Then I created a list to hold “some” people and then printed their values. It is also a similar code.

using System;
using System.Net.Http;
using System.Collections.Generic;

namespace HelloWorld
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            // Create the list of people.
            var people = new List<Person>();

            people.Add(new Person
            {
                Name = "Afzaal Ahmad Zeeshan",
                Age = 20
            });

            people.Add(new Person
            {
                Name = "Sofiya Zeeshan",
                Age = 19
            });

            people.Add(new Person
            {
                Name = "Daniyal Ahmad Rizwan",
                Age = 15
            });

            people.Add(new Person
            {
                Name = "Eminem",
                Age = 43
            });

            // Printing the details for people.
            foreach (var person in people)
            {
                Console.WriteLine(person);
            }
        }
    }

    class Person
    {
        // Provide the attributes.
        public string Name { get; set; }
        public int Age { get; set; }

        // Override the default ToString
        public override string ToString()
        {
            return string.Format("[Person: Name={0}, Age={1}]", Name, Age);
        }
    }
}

How this code ran, please see below.

It just prints everything and then terminates. These were a few basic things. Let’s try out if C# still has the same power or not, why not try out Internet access in C#?

Using C# to access online resources

Now in this section, I will be referring to an online API of my own to access the data. This may make things a bit tough if you have never worked with System.Net namespaces in the .NET framework. I will be using an object from this namespace and then I will call the functions to download the data from an online API and then I will print it.

Linux also provides a similar manner to use the TCP/IP protocol which is why C# code written for Windows would work similarly with Linux and other Mac’s OS X systems.

In the following code, I have also used another concept in C#, asynchronous programming. Mono supports async models of C#, and you can avail of the services right in the IDE, just like Visual Studio. The code I have used is like the one below.

using System;
using System.Net.Http;
using System.Collections.Generic;

namespace HelloWorld
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            downloadAndPrint();
        }

        private static void downloadAndPrint()
        {
            System.Threading.Tasks.Task.Run(async () =>
            {
                using (var client = new HttpClient())
                {
                    Console.WriteLine("Downloading the data...");
                    var message = await client.GetStringAsync("http://afzaalahmadzeeshan.gear.host/api/sample");
                    Console.WriteLine();
                    Console.WriteLine(message);
                }
            }).Wait();

            Console.WriteLine("Exiting the function..");
        }
    }
}

The above code simply downloads the response as a string and prints it. This shows, that C# not only just works in the console, but also works perfectly with the protocols on different systems. All of this is managed by the Mono Runtime.

So, I guess this is enough to demonstrate how C# can be used.

References

A few topics that you should consider reading:

1. The Mono Runtime
2. HttpClient Class
3. List<T> Class
4. Asynchronous Programming with Async and Await

Points of Interest

In this article, I have demonstrated how you can use C# to develop cross-platform applications. There is no need to learn multiple languages to target multiple frameworks and application systems. You can use one single programming language, even C#, and write native applications on multiple platforms.

Although C# doesn’t execute natively, even on those platforms. Mono Runtime is responsible for executing the applications on those platforms. Just like. NET’s virtual machine or Windows Runtime executes C# code on Windows environments. On other platforms (and including Windows if compiling and using Mono), you can use Mono Runtime to target the platforms and make use of .NET libraries and lightweight programming models of C# programming language.

I hope you like this article, wait up for the next articles, or write back to me to get more.