How To Create Pagination Using LINQ In C#

Introduction

 

This example demonstrates how to create pagination using LINQ in C# desktop applications.

 

Implementation

 

So, lets start implementation of our example.

 

Step 1 Open your Visual Studio and create a new project.

 

Step 2 Now, design a form like this.

 

 

 

Step 3 Create a class with the name SampleData.cs and write the following code in it.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    public class SampleData
    {
        public int ID;
        public string Name;
        public string Age;
        public string Address;

        public SampleData()
        {
        }
    }
}

Step 4 Write the following code within class.

List<SampleData> _sampleDataList = new List<SampleData>();

Step 5 Write the following code at the time of constuctor creation. 

int currentPage = 0;
int currentSize = 10;

public SampleForm()
   {
       InitializeComponent();
       //i Created a dummy data to use for pagination
       CreateDummy();
       currentPage = 0;
       Paging(currentPage, currentSize);
   }

Step 6 Now, create the following function.

private void Paging(int pagenum, int pagesize)
       {

           if (currentPage < 0) { currentPage = 0; return; }

           flowLayoutPanel1.Controls.OfType<Label>().Where(e => e.Tag.ToString() != (pagenum + 1).ToString())
               .ToList().ForEach((element) =>
               {
                   element.ForeColor = Color.Black;
               });

           flowLayoutPanel1.Controls.OfType<Label>().Where(e => e.Tag.ToString() == (pagenum + 1).ToString())
               .First().ForeColor = Color.Red;



           textBox1.Text = "Page " + (pagenum + 1) + " of " + (int)(_sampleDataList.Count / pagesize);

           var products = from p in _sampleDataList.Skip(pagenum * pagesize).Take(pagesize)
                          select new { ID = p.ID, Name = p.Name, Age = p.Age, Address = p.Address };

           dataGridView1.DataSource = products.ToList();
       }

private void CreateDummy()
      {
          Enumerable.Range(1, 100).ToList().ForEach((element) =>
          {
              SampleData s = new SampleData();
              s.ID = element;
              s.Name = "FullName" + element;
              s.Age = new Random().Next().ToString();
              s.Address = "Davao";

              _sampleDataList.Add(s);
          });

          Enumerable.Range(1, (_sampleDataList.Count() / currentSize)).ToList().ForEach((element) =>
          {
              Label lbl = new System.Windows.Forms.Label();
              lbl.AutoSize = true;
              lbl.Location = new System.Drawing.Point(3, 0);
              lbl.Name = "lbl" + element;
              lbl.Size = new System.Drawing.Size(61, 13);
              lbl.Text = element.ToString();
              lbl.Tag = element;

              lbl.Click += new EventHandler(lbl_Click);

              this.flowLayoutPanel1.Controls.Add(lbl);
          });
      }

Step 7 Write  the following code in click event of button1,2,3 and button4.

private void button1_Click(object sender, EventArgs e)
       {
           currentPage = 0;
           Paging(currentPage, currentSize);
       }

       private void button2_Click(object sender, EventArgs e)
       {
           currentPage = (currentPage - currentSize) < 0 ? (currentPage - 1) : 0;
           Paging(currentPage, currentSize);
       }

       private void button3_Click(object sender, EventArgs e)
       {
           currentPage = ((currentPage + 1) * currentSize) < _sampleDataList.Count() ?
               (currentPage + 1) : currentPage;
           Paging(currentPage, currentSize);
       }

       private void button4_Click(object sender, EventArgs e)
       {
           currentPage = (_sampleDataList.Count() / currentSize) - 1;
           Paging(currentPage, currentSize);
       }

Step 8 Run the project and you can see the following output on your screen.

 

 

Summary

 

In a large set of data, pagination is a reliable technique to find the record from the record list.