LINQ to memory objects in the .NET Compact Framework

Language-Integrated Query (LINQ) adds general-purpose query facilities to the .NET Compact Framework that apply to various sources of information such as relational databases, XML data, and in-memory objects,
 
Here we define the LINQ to memory objects, we use list data type as the memory object to hold the data.
 
Entity.cs Class
 

using System;
using System.Collections.Generic;
using System.Linq;
namespace LINQ_test
{
    public  class entity
    {
 
        public   string name
        {
            get;
            set;
        }
    }
}
 
//Linq form 

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Collections;
 
namespace LINQ_test
{
    public partial class Linq : Form
    {
        List<entity> li = new List<entity>();
        
        public Linq()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {           
           entity er= new entity();
           er.name = textBox1.Text;
           li.Add(er);
 
           textBox1.Text = "";
           ArrayList Alist = new ArrayList();
           var varlinq = from p in li where p.name.Length < 4
                     select p;
 
            foreach (var data in varlinq)
 
            Alist.Add(data);
 
            dataGrid1.DataSource =  Alist;           
        }
 
        private void button2_Click(object sender, EventArgs e)
        {
            ArrayList  Alist = new ArrayList();
            var varlinqnext = from p in li
                     select p;
 
            foreach (var data in varlinqnext)
 
               Alist.Add(data);
 
            dataGrid1.DataSource = Alist;             
        }
    }
}