Поиск  
Always will be ready notify the world about expectations as easy as possible: job change page
May 16

You have been doing pagination wrong in .NET 6

Автор:
Источник:
Просмотров:
1830

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
Jun 3
Author: Dayanand Thombare
Introduction Delegates are a fundamental concept in C# that allow you to treat methods as objects. They provide a way to define a type that represents a reference to a method, enabling you to encapsulate and pass around methods as...
Jan 7
Author: Sebastian Stupak
Few days ago I stopped myself while writing code. I wrote my LINQ filtering wrong. items.Where(x => x > 0).Any(); (Obviously, it’s a pseudo code) I realized my mistake immediately, changed the code, and went on with my day. Then...
Jun 28
Author: ByteHide
Are you preparing for an interview that will involve C# asynchronous programming? You’ve come to the right place! This comprehensive article covers a wide range of C# async-await interview questions that will test your understanding of the async-await pattern, along...
Apr 18
Author: Michael Shpilt
One of the most used databases these days is PostgreSQL (aka Postgres). Its accomplishments include being the most popular DB [among professional developers] according to Stack Overflow survey of 2022, the database in all of the fastest TechEmpower benchmarks, and...
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