• Go to Visual Studio 2010.
• Go to File �  New �  Project.
• Select Windows Application and apply the following settings to your project: 
  Target Framework: .NET 3.5
  Build output: AnyCpu (or x64)
• Click Add.

Next, we need to add references to the Client Object Model in order to be able to work with the client-side APIs from our Windows Application.

Right click the “References” node and choose “Add Reference”  

·         Choose Browse:

·       Go to the following location:C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\ISAPI.

·         Select these two files:

Microsoft.SharePoint.Client.dll

Microsoft.SharePoint.Client.Runtime.dll

  Add the following controls in your Windows Application Form:

·         A new DataGridView control

·         A new Button control

After adding controls you have to write the following code to access external list data:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using SP1 = Microsoft.SharePoint;
using SP = Microsoft.SharePoint.Client;
 
namespace AccessExternalListData
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            // Define the Client Context (as defined in your textbox)
            SP.ClientContext context = new SP.ClientContext("http://rohit:34143/");
            SP.Web site = context.Web;
 
            var StudentList = site.Lists.GetByTitle("StudentList");
 
            SP.CamlQuery camlQuery = new SP.CamlQuery();
 
            IQueryable<SP.ListItem> students = 
                                           StudentList.GetItems(camlQuery);                                           StudentList.GetItems(camlQuery);
            IEnumerable<SP.ListItem> externalList = context.LoadQuery(students);
            context.ExecuteQuery();
 
            var studentListData = from student in externalList
              select new
              {
                  // We're never pointing to the field at the 0-index
                  // because it's used by the BDC Identity itself. Hence our elements 
                      start at 1.                      start at 1.
                  StudentID = student.FieldValues.ElementAt(1).Value.ToString(),
                  StudentName = student.FieldValues.ElementAt(2).Value.ToString(),
                  StudentCourse = student.FieldValues.ElementAt(3).Value.ToString()
              };
 
            // Simply clear the rows and columns of the GridView
            gvStudents.Rows.Clear();
            gvStudents.Columns.Clear();
 
            // Add the columns we need (ProductID, Name, Description)
            gvStudents.Columns.Add("StudentID", "StudentID");
            gvStudents.Columns.Add("Name", "Name");
             gvStudents.Columns.Add("Course", "Course");
            foreach (var stud in studentListData)
            {
                // For each product in the list, add a new row to the GridView
               gvStudents.Rows.Add(stud.StudentID, stud.StudentName, stud.StudentCourse);
            }
        }
    }
}

 When you run this application and click on button (Display List) it will look something like this:        

Thanks for reading this article. I think this will help you a lot.