Asp.Net Mvc Overview Of The .Net Platform And Clr Complete Guide

Step 1: Understanding .NET Platform Overview

What is .NET?

.NET (pronounced "dot net") is a general-purpose development platform maintained by Microsoft that provides a comprehensive and consistent programming model for building applications that have visually stunning user experiences, seamless and secure communication, and the ability to use the computing resources of modern and diverse hardware and cloud environments.

.NET Framework vs .NET Core vs .NET 5 and beyond

• .NET Framework: Initially released in 2002, it is a mature, stable, and well-tested framework.
• .NET Core: A cross-platform version of .NET that can be used on Windows, macOS, and Linux. It is more lightweight and modular.
• .NET 5: A unified and modern version of .NET that merged .NET Core and .NET Framework. It supports all the applications .NET Framework and .NET Core supported.

Key Components of .NET Platform:

• Common Language Runtime (CLR): Manages the execution of .NET applications.
• .NET Framework Libraries: A large collection of libraries and tools that help developers to build various types of applications.
• Development Tools (Visual Studio): Integrated development environment (IDE) that provides the tools needed to build .NET applications.

Step 2: Understanding the Common Language Runtime (CLR)

What is CLR?

CLR is the execution engine of .NET. It is responsible for several key functions:

• Memory Management: Manages the memory of the applications and frees up unused memory.
• Security: Provides a secure environment for .NET applications.
• Exception Handling: Implements try-catch blocks.
• Code Verification: Checks all code before it runs.

How CLR Works:

1. Compilation: The source code is compiled into Intermediate Language (IL) code.
2. Execution: The CLR uses Just-In-Time (JIT) compiler to convert IL into machine code.
3. Garbage Collection: CLR automatically frees up memory when objects are no longer used.

Practical Example: Understanding CLR with a Simple .NET Application

Let's create a simple console application to see how CLR works under the hood.

1. Create a New Console Application in Visual Studio:

   • Open Visual Studio.
   • Go to File > New > Project.
   • Select Console App (.NET Core) and click Next.
   • Name your project CLRConsoleApp and click Create.

2. Write a Simple C# Program:

using System;

namespace CLRConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello, World from CLRConsoleApp!");
        }
    }
}

3. Build the Application:

   • Click on Build > Build Solution.
   • Notice the output folder will contain a .dll file. This is the IL code.

4. Use ILSpy to View IL Code:

   • Download and install ILSpy.
   • Open ILSpy.
   • Drag and drop the .dll file into ILSpy.
   • You will see the IL code for your program.

5. Run the Application:

   • Click on Start or F5 to run the application.
   • Notice the console window shows the message Hello, World from CLRConsoleApp!.

Step 3: Introduction to ASP.NET MVC

What is ASP.NET MVC?

ASP.NET MVC (Model-View-Controller) is a robust and strongly typed server-side web application framework that implements the MVC architectural pattern. It enables the separation of application concerns, facilitates easier test-driven development (TDD), and helps in building scalable web applications.

Key Components of ASP.NET MVC:

• Model: Represents the data layer of the application and also contains the logic for business flow within the application.
• View: Represents the User Interface layer of the application and contains the application's display logic.
• Controller: Acts as an interface between Model and View components to process all the business logic and incoming requests, manipulate data using the Model component and interact with the Views to render the final output.

Practical Example: Creating a Simple ASP.NET MVC Application

Let's create a simple ASP.NET MVC application step-by-step.

1. Create a New MVC Project:

   • Open Visual Studio.
   • Go to File > New > Project.
   • Select ASP.NET Core Web App (Model-View-Controller) and click Next.
   • Name your project ASPNETMVCApp and click Create.
   • Select the version of .NET you want to use and click Create.

2. Understand the Project Structure:

   • Controllers: Contains Controller classes.
   • Models: Represents the data layer.
   • Views: Contains views (Razor files) that are rendered by the controller.
   • wwwroot: Contains static assets like JavaScript, CSS, and images.

3. Create a Simple Model:

   • Right-click on the Models folder, select Add > Class.
   • Name it Employee.cs and add the following code:

namespace ASPNETMVCApp.Models
{
    public class Employee
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Department { get; set; }
    }
}

4. Create a Controller:
   • Right-click on the Controllers folder, select Add > Controller.
   • Select MVC Controller - Empty and name it EmployeeController.cs.
   • Add the following code:

using Microsoft.AspNetCore.Mvc;
using ASPNETMVCApp.Models;

namespace ASPNETMVCApp.Controllers
{
    public class EmployeeController : Controller
    {
        public IActionResult Index()
        {
            var employee = new Employee
            {
                Id = 1,
                Name = "John Doe",
                Department = "IT"
            };

            return View(employee);
        }
    }
}

5. Create a View:
   • Right-click inside the Index() method, select Add View.
   • Name the view Index, select Employee as the model, and click Add.
   • Add the following code to Index.cshtml:

@model ASPNETMVCApp.Models.Employee

<h2>Employee Details</h2>

<div>
    <h4>Name: @Model.Name</h4>
    <h4>Department: @Model.Department</h4>
</div>

6. Run the Application:
   • Click on Start or F5 to run the application.
   • Navigate to /Employee/Index in the browser.
   • You will see the employee details displayed on the page.

Step 4: Conclusion

This guide provided an overview of the .NET platform, focusing on the CLR and introduced ASP.NET MVC through practical examples. By creating a simple console application and an ASP.NET MVC application, you should have a good understanding of how the .NET platform works, how CLR manages the execution of applications, and how to build web applications using ASP.NET MVC.