How-to Guide: Building Your First ASP.NET Core Web Application

Introduction
ASP.NET Core is a powerful, open-source framework for building modern, cloud-based, and internet-connected applications. Whether you're a beginner or an experienced developer, creating your first ASP.NET Core web application is a crucial step in understanding how to leverage the full potential of the .NET ecosystem. This guide will walk you through the process of building a basic web application using ASP.NET Core.

Table of Contents

1. Setting Up Your Development Environment Installing .NET SDK Installing Visual Studio Creating a New Project
2. Understanding the Project Structure Key Files and Folders Configuration Files
3. Creating Your First Web Page Adding a Controller Creating a View
4. Implementing a Basic Model Adding a Model Class Using the Model in a Controller and View
5. Connecting to a Database Configuring Entity Framework Core Creating and Applying Migrations
6. Adding User Authentication Setting Up Identity Registering and Logging In Users
7. Deploying Your Application Publishing Your Application Deploying to IIS or Azure
8. Conclusion

Setting Up Your Development Environment
Installing .NET SDK
First, you need to install the .NET SDK. Visit the official .NET download page and download the SDK for your operating system. Follow the installation instructions provided on the website.
Installing Visual Studio
Next, install Visual Studio, which is a powerful integrated development environment (IDE) for .NET development. Download it from the Visual Studio website and select the ASP.NET and web development workload during installation.
Creating a New Project
Open Visual Studio.
Click on "Create a new project."
Select "ASP.NET Core Web Application" and click "Next."
Name your project, choose a location to save it, and click "Create."
Select ".NET Core" and "ASP.NET Core 5.0" (or the latest version), then choose the "Web Application (Model-View-Controller)" template and click "Create."

Understanding the Project Structure
Key Files and Folders

• wwwroot: Contains static files like CSS, JavaScript, and images.
• Controllers: Holds controller classes responsible for handling incoming requests and returning responses.
• Models: Contains classes that represent the data and business logic of the application.
• Views: Holds Razor view files that define the UI of the application. appsettings.json: Configuration file for application settings.

Creating Your First Web Page
Adding a Controller
Right-click on the "Controllers" folder.
Select "Add" > "Controller..."
Choose "MVC Controller - Empty" and click "Add."
Name your controller "HomeController."
Creating a View
Right-click inside the "Index" action method in HomeController.
Select "Add View..."
Name the view "Index" and click "Add."
Edit the generated Index.cshtml file to include some HTML content.

Implementing a Basic Model
Adding a Model Class
Right-click on the "Models" folder.
Select "Add" > "Class..."
Name the class "Product" and click "Add."
Define properties for the Product class, such as Id, Name, and Price.
Using the Model in a Controller and View
Modify HomeController to include a list of products.
Pass the product list to the Index view.
Update the Index.cshtml to display the products.

Connecting to a Database
Configuring Entity Framework Core
Install the Entity Framework Core NuGet packages.
Configure the database context in Startup.cs.
Creating and Applying Migrations
Create a new DbContext class.
Add a connection string to appsettings.json.
Use the Package Manager Console to add and apply migrations.

Adding User Authentication
Setting Up Identity
Install the ASP.NET Core Identity NuGet package.
Configure Identity services in Startup.cs.
Registering and Logging In Users
Scaffold Identity pages.
Update the layout to include login/logout links.

Deploying Your Application
Publishing Your Application
Right-click on the project and select "Publish."
Choose a publish target (e.g., Folder, IIS, Azure).
Deploying to IIS or Azure
Follow the instructions to deploy to your chosen target.
Verify that your application is running correctly in the deployed environment.

Conclusion
Building your first ASP.NET Core web application is an exciting journey that equips you with essential skills for web development. By following this guide, you have learned how to set up your development environment, create a basic web page, implement a model, connect to a database, add user authentication, and deploy your application. Continue exploring the vast capabilities of ASP.NET Core to build robust, high-performance web applications.