Advertisement
Поиск  
Always will be ready notify the world about expectations as easy as possible: job change page
Feb 26

You have been doing pagination wrong in .NET 6

Автор:
Источник:
Просмотров:
663

Pagination is in front of us everyday yet we take it for granted kind of like we do with most things. It’s what chunks huge lists of data (blog posts, articles, products) into pages so we can navigate through data.

This is how you did pagination until this point.

Pagination

using System;

public class Article
{
    public int Id;
    public string Title;
    public string Content;
    public int AuthorId;
    
    public List<Article> GetArticles()
    {
        return new List<Article> {
            new Article {Id = 1, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 2, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 3, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
            new Article {Id = 4, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 5, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 6, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
            new Article {Id = 7, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 8, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 9, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
            new Article {Id = 10, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 11, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 12, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
        };
    }
}

public class Program
{
    public static void Main()
    {
        List<Article> articles = new Article().GetArticles();
        int pageNumber = 1;
        int itemsPerPage = 5;

        IEnumerable<Article> page = articles.Skip((pageNumber - 1) * itemsPerPage).Take(itemsPerPage);

        Console.WriteLine($"Page: {pageNumber}");
        foreach(Article article in page)
        {
            Console.WriteLine($"    Id: {article.Id}, Title:{article.Title}, Content:{article.Content}, AuthorId:{article.AuthorId}");
        }
    }
}

And now this is how you can achieve the same result but in a more readable way using the Chunk method.

Chunk

using System;

public class Article
{
    public int Id;
    public string Title;
    public string Content;
    public int AuthorId;
    
    public List<Article> GetArticles()
    {
        return new List<Article> {
            new Article {Id = 1, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 2, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 3, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
            new Article {Id = 4, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 5, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 6, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
            new Article {Id = 7, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 8, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 9, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
            new Article {Id = 10, Title = "Best title one", Content = "Amazing content", AuthorId = 1},
            new Article {Id = 11, Title = "Another title", Content = "More amazing content", AuthorId = 1},
            new Article {Id = 12, Title = "Unicorns", Content = "Even more amazing content", AuthorId = 1},
        };
    }
}

public class Program
{
    public static void Main()
    {
        List<Article> articles = new Article().GetArticles();
        int pageNumber = 1;
        int itemsPerPage = 5;

        IEnumerable<Article[]> allPages = articles.Chunk(itemsPerPage);

        Console.WriteLine($"Page: {pageNumber}");
       
        foreach(Article article in allPages.ElementAt(pageNumber - 1))
        {
            Console.WriteLine($"    Id: {article.Id}, Title:{article.Title}, Content:{article.Content}, AuthorId:{article.AuthorId}");
        }
    }
}

There’s nothing wrong with using the first method to do pagination. The Chunk method is a new way of doing achieving the same result but with a cleared code. It takes only one parameter, the maximum size of each chunk (largest numbers of items per page). Is important to note that the Chunk method is only available in .NET 6.

Conclusion

This is another way to do things, another tool in your arsenal so you can use both. 

Похожее
Jan 16, 2023
C# AngleSharp tutorial shows how to parse HTML in C# with AngleSharp library.The library can also parse SVG, MathML, or XML.AngleSharp GitHub: https://github.com/AngleSharpDocument Object Model (DOM) is a standard tree structure, where each node contains one of the components from...
Sep 6, 2023
Author: Kenji Elzerman
To write files with C#, you have to know how to do it. The basics aren’t rocket science. There are a few lines of code you need to know. But writing and reading files with C# is something every beginning...
Apr 8
Author: João Simões
Performance comparison between LinkedList and ToArraySome weeks ago I created an article comparing the performance of ToList versus ToArray when creating short lived collections that won’t be mutated, usually used to prevent multiple enumerations when iterating over a temporary LINQ...
Jul 11, 2021
Author: Sasha Mathews
In C#, reference types can be assigned null values. This is something that developers will have to live with until they use classes to create software. Unfortunately, the folks at Microsoft cannot simply disallow null assignment to reference variables at...
Написать сообщение
Почта
Имя
*Сообщение


© 1999–2024 WebDynamics
1980–... Sergey Drozdov
Area of interests: .NET Framework | .NET Core | C# | ASP.NET | Windows Forms | WPF | HTML5 | CSS3 | jQuery | AJAX | Angular | React | MS SQL Server | Transact-SQL | ADO.NET | Entity Framework | IIS | OOP | OOA | OOD | WCF | WPF | MSMQ | MVC | MVP | MVVM | Design Patterns | Enterprise Architecture | Scrum | Kanban