Chapter 2: An Introduction to ASP.NET Core in Layman‘s Terms

第1章 框架学习的基础与实用策略

Chapter 2: An Introduction to ASP.NET Core in Layman‘s Terms

章节 3: 制作最小化API应用

第4章 .NET 8.0 ASP.NET Core BookQuerySystem: Project Layout

第5章：.NET 8.0 ASP.NET Core中的中间件及其在书籍管理系统中的应用

1.What is the ASP.NET Core Framework

ASP.NET Core is an exceptional framework that is free to use on any mainstream system, such as Windows, Linux, or macOS. It is fully open-source, meaning you can view and modify its internal code. This framework is specifically designed to help developers create modern, efficient websites, web applications, and API services. It leverages the power of the .NET platform and the C# language to achieve this.
With ASP.NET Core, you have the flexibility to choose whether to host your application in the cloud or on your own computer. This allows you to take advantage of cloud services, such as automatically scaling resources based on demand, making your application more robust and flexible. However, if you prefer to have full control, you can manage your application directly on your computer.

More importantly, ASP.NET Core plays a crucial role in seamless integration across various operating systems, allowing developers to harness the optimal environment suited to their specific requirements. In brief, ASP.NET Core provides developers with the capability to craft robust solutions for creating exceptional web applications and APIs tailored to their needs.

2.Types of Applications that can be Built with ASP.NET Core Framework

The ASP.NET Core framework offers developers the ability to create a variety of robust applications, paralleling the development of a comprehensive ecosystem. This platform supports diverse application types such as web apps that deliver content directly to servers, back-end systems managing intricate business logic, and HTTP API interfaces that seamlessly integrate mobile apps with servers. Additionally, it excels in the Internet of Things (IoT) domain by addressing connectivity challenges for various devices. With the growing popularity of artificial intelligence, ASP.NET Core continues to play an indispensable role in data processing and machine learning deployment. By leveraging .NET's ML.NET libraries alongside ASP.NET Core, developers can implement machine learning models directly within their web applications. These models enable intelligent predictions and analyses of user input data, enhancing application capabilities and delivering more personalized and precise services.

Which are the common application types that ASP.NET Core supports? Some examples include

Minimal APIs: These lightweight Minimal APIs are specifically designed for mobile applications or Single-Page Applications (SPAs).
Web APIs: If you require a comprehensive and well-structured HTTP API service, Web APIs are your best choice.
gRPC APIs: When efficient communication between servers is necessary, gRPC comes into play. They utilize the gRPC protocol to ensure faster and more efficient API communication.

Razor Pages: If you prefer a page-based development approach, Razor Pages eases the page development process, making the task of building server-side rendered applications more straightforward.

MVC Controllers: When dealing with intricate server-side application logic, MVC Controllers provide an organized framework. They utilize the Model-View-Controller architectural pattern to organize your application logic and do not restrict functionality beyond front-end rendering.

Blazor WebAssembly: Envision running .NET code directly in your browser – Blazor WebAssembly makes this functionality available. By leveraging WebAssembly technology, it delivers outstanding performance for your Single-Page Applications, offering a seamless and efficient user experience on par with popular JavaScript-based frameworks such as Angular, React, and Vue.

Blazor Server: If you're looking for the Single-Page Application experience without giving up on server-side convenience and performance, Blazor Server is perfect. By leveraging WebSockets, it enables real-time UI interactions and page updates seamlessly. It provides an efficient way to deliver content dynamically across a network, ensuring that all users receive the latest updates without delay. Dynamic content delivery over a network is efficiently managed by Blazing Server, ensuring immediate updates for all users without any lag. By balancing client-side and server-side performance equally, Blazing Server becomes an excellent choice for large-scale applications.

These application building patterns are built upon ASP.NET Core's central component framework, which includes infrastructure such as configuration management and logging. Each application pattern builds upon the functionality set for specific scenarios, while maintaining these common characteristics.

When selecting the most appropriate application architecture paradigm, experts must thoroughly assess a range of critical factors including API-specific demands, interoperability with existing systems, client-side runtime environments, scalability requirements, and stability criteria. The ASP.NET Core framework exemplifies remarkable versatility by enabling both singular approach selection and the integration of diverse methodologies within a unified platform.

3.Why Choose ASP.NET Core Framework

When selecting the ASP.NET Core framework, it is crucial to consider its merits in detail. In fact, it shares many desirable qualities with other prominent platforms and frameworks, such as its ability to run on various operating systems (cross-platform compatibility), its speed and ease of scaling up (performance and scalability), a modern feel during development (modern development experience), built-in security mechanisms for data protection (inherent security features), flexibility in deployment strategies (versatile deployment options), and a robust community support system ready to assist with problem-solving (comprehensive community resources).

Despite its many advantages, these factors were not the main reasons behind my decision to adopt ASP.NET Core. Among the numerous strengths of ASP.NET Core, one standout feature that solidified my choice was its exceptional support for lone developers. The learning curve for ASP.NET Core is remarkably gentle, akin to a downhill slope—beginners can easily master the platform and begin developing projects without difficulty.

Moreover,它采用C#语言的能力尤为突出，在语法上的清晰度以及其强大的表达能力都堪称完美。此外，在书籍、视频教程等多种形式下提供了丰富的学习资料。这些全面的学习资源为像我们这样的独立开发者提供了迅速将想法转化为实际应用的保障，在保证速度的同时也确保了质量。

4.ASP.NET Core Applications Handling HTTP Requests and Responses

The ASP.NET Core framework stands out as a key tool for developing websites and applications. Its primary role is to streamline the creation of high-performance, scalable web applications that ensure efficient data transfer from servers to computers or mobile devices. For professionals engaged in web development, crafting visually attractive and user-friendly websites within browsers presents both challenges and opportunities.

Imagine entering an internet address or URL into your browser; it’s akin to stepping into a gateway that opens up an entire new dimension. The URL acts as an online map, routing users directly to specific websites and their designated sections. This relies on HTTP, an essential communication protocol, connecting your computer or mobile device with the server hosting the website so that you can access its content effectively.

When focusing on website names or hostnames, they serve as identity cards for websites across the internet. Leveraging DNS (Domain Name System), these hostnames are translated into unique numerical addresses (IP addresses), enabling computers worldwide to locate them. For instance, consider microsoft.com for Microsoft's website and baidu.com for Baidu; through DNS, it becomes possible for us to effortlessly find what we're seeking online, reaping the benefits of internet convenience.

Exploring the fascinating world of HTTP! Those who may not be familiar with it might find it intriguing to know that HTTP stands for HyperText Transfer Protocol. It functions as a foundational protocol that allows websites to operate seamlessly across the internet. Imagine it as a message relay system: The client (whether your computer or mobile device) initiates communication by sending a request to the server (which can be likened to a vast repository housing all your favorite websites). Once you pose your query, such as "What's up with that new feature?", the server efficiently retrieves and processes your request before responding with an answer.

Each request includes an action (verb) and specifies where something (path) should be placed. The action can be commands like 'give me' or 'tell me,' while the path indicates where the requested item is stored. Requests may also feature additional metadata (headers), similar to labels on packages, offering more details about what's being requested. Occasionally, extra content (body) accompanies these requests, akin to gifts sent via email.

Upon accepting a request, a server returns an acknowledgment message similar to an invoice issued by courier services. This acknowledgment clearly indicates whether your query has been successfully processed or if any issues have occurred. Additionally, this acknowledgment may include header information and detailed content related to your inquiry.

The information begins its travel across the internet's vast expanse. Similar to a message in transit, it may pass through various terrains and vast expanse before reaching its intended server with a specific name. Upon arrival at its destination server, a web application is waiting to handle this information.

On this journey, the information is temporarily stored at several points known as routers, where it is examined before transmission. Processing does not commence until the data reaches a specific server location.

Once it connects to the server, it operates as an illusionist, converting the message content into an HTTP response. This HTTP response might include an impressive webpage design, crisp imagery for images or high-quality photos taken by advanced cameras. It could also feature JavaScript animation engines to dynamically illustrate webpages. Additionally, it might simply state "received" in plain text or offer any other functionality you imagine.

Upon clicking a link on the webpage, one requests information from the server. The server subsequently assembles an HTML document into a package and sends it as part of an HTTP response quickly through the internet's fast route.

Upon receiving this gift,the browser responds immediately.It does not merely display raw HTML code but instead generates a fully functional webpage according to embedded instructions.When additional resources such as images or JavaScript are mentioned in remote server's documentation,the browser retrieves them sequentially until all required components are loaded.

Whether it's HTML, images, CSS, or JavaScript, they're all transmitted using the same HTTP request-loopback mechanism. On this extensive platform of the internet, this process continuously unfolds, establishing the foundation for web content delivery.

Although simple webpages typically involve only a small number of requests, complex modern websites may hide numerous request and response transactions within their intricate architecture.

With a solid foundation in this process, you are now equipped to delve deeper into its intricacies. As a powerful framework, ASP.NET Core effortlessly generates robust HTTP responses.

5.Handling Requests in ASP.NET Core

In the world of ASP.NET Core, constructing a website is akin to setting up a performance where characters are personified by browsers and servers through an intricate conversation framework. ASP.NET Core functions as an integral part of this production environment by handling tasks such as validating request authenticity, managing login data securely, and creating visually appealing web interfaces. Picture this: The process begins when you interact with your browser—sending out invitations that engage ASP.NET Core's active role in shaping your web experience. When you initiate interaction with your browser, you send an invitation that triggers ASP.NET Core's involvement in your web experience. This coordination ensures seamless user engagement by translating incoming invitations into internal terms like HttpContext for effective communication with your web application. The default server role known as Kestrel acts as an discreet intermediary within this dynamic system. Intercepting incoming invitations and converting them into internal terms like HttpContext for effective communication with your web application.

借助于这个= window, 该网站识别出您的需求并准备好作出回应. 它可能会向您展示一个视觉效果极佳的网页, 告知您"您无法访问此区域", 或协助您发送邮件. 所有这些回应都是由网站的智慧与技能精心打造而成, 在仔细分析= window中的相关信息后完成.

Once a website has prepared its response, Kestrel acts again. The system then reformats these responses—essentially a collection of numerical and alphabetical data—into the standard HTTP format, which is transmitted back through the network to your browser.

The process unfolds as if it's a lively performance, with HTTP requests and responses smoothly interacting as they grace your interface without you being aware of all their intricate details. In reality, what happens is that all these interactions are orchestrated behind the scenes within your ASP.NET Core website. Where technology and creativity come together seamlessly to create something truly exceptional.

6.Front-end and Back-end Separation

Blazor simplifies front end and back end separation, making it an incredibly efficient approach for building modern web applications. In this tutorial, I will demonstrate how to integrate Blazor effectively so you can fully leverage its benefits. Let us begin by exploring the core concepts behind Blazor:
Suppose you're a C# developer eager to enhance your web development skills, yet find yourself navigating a landscape predominantly focused on JavaScript. This can be quite perplexing as you realize you'll need to learn an entirely new paradigm while dedicating significant time to practice. Fortunately, JavaScript possesses many features that align with C#, though mastering its intricacies requires dedication and effort.

That’s where Blazos steps in as a hero, enabling you to code the client-side portion of your web pages directly in C#, removing the necessity to learn another language. This framework provides two versions: one for server-based applications and another optimized for WebAssembly.

Blazor Server functions as an intermediary, operating in persistent communication with your ASP.NET Core server. Your C# code actually executes on the server side. This implies, while the code is not directly executed in the browser, coding remains just as straightforward as writing C# for the backend.

Blazor WebAssembly, on the other hand, excels even further. It allows your C# applications to run seamlessly within browsers, rendering high-quality visuals and animations. This provides a more responsive and seamless interaction for users.

Certainly, both versions of Blazor do not offer a universal solution; each has its own specific use cases. These solutions cater to different application scopes. However, Blazor has introduced new avenues for the future of ASP.NET Core by empowering C# developers to excel in front-end applications.

As soon as you grasp the flow of requests and responses within ASP.NET Core, this tutorial aims to reveal the techniques behind creating effective responses. Through this tutorial, we'll guide you into the inner workings of ASP.NET Core. We'll explore its mechanisms as we delve into its architecture while highlighting its capacity to generate remarkable outcomes efficiently. This course is designed to be both enlightening and engaging. Each module is crafted to provide comprehensive insights into core concepts while enhancing your technical skills throughout.

My motivation for writing this tutorial is clear: to create an enjoyable learning experience rather than a tedious one. In each of the following chapters, I will strive to teach concepts in diverse methods that keep learning exciting and fun. However, this chapter functions as an introduction, preparing you mentally and emotionally for the thrilling journey ahead! 😊