Introduction

If you read MSDN you will be hard pressed to find out how to bind a business object to a datagrid. I thought to make up for the lack of business object documentation; I would write a simple tutorial on how to bind an object to a datagrid.

First Create Your Class

First let’s create a normal class nothing fancy:

using System;

namespace Employee
{

 public class Employee
 {
  public Employee()
  {   
  }
  
  #region Employee Accessors
  
  private string _firstName;
  private string _lastName;
  private int _employeeNumber;
  
  public string FirstName
  {
   get
   {
    return _firstName;
   }
   set
   {
    _firstName = value;
   }
  }
  
  
  public string LastName
  {
   get
   {
    return _lastName;
   }
   set
   {
    _lastName = value;
   }
  }
  
public int EmployeeNumber
  {
   get
   {
    return _employeeNumber;
   }
   set
   {
    _employeeNumber = value;
   }
  }
  #endregion
 }
}

Create a collection of your Business Object

The MSDN documentation doesn't give you a concrete example of binding using a business object but they do say that a datagrid is able to bind to anything that implements the IList (single dimension arrays implement the IList interface), IListSource, or IBindingList interfaces.

Reference: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbcon/html/vbtskbindingthedatagridcontroltoanadodataset.asp

So we will make a collection class of Employee objects that implement the IList interface:

using System;

using System.Collections;

namespace Employee

{

      public class EmployeeCollection : CollectionBase

      {

            public Employee this[int index]

            {

                  get

                  {

                        return (Employee)List[index];

                  }

                  set

                  {

                        List[index] = value;

                  }

            }

            public int Add(Employee value)

            {

              return (List.Add(value));

            }

            public int IndexOf(Employee value)

            {

              return (List.IndexOf(value));

            }

            public void Insert(int index, Employee value)

            {

              List.Insert(index, value);

            }

            public void Remove(Employee value)

            {

              List.Remove(value);

            }

            public bool Contains(Employee value)

            {

              return (List.Contains(value));

            }

      }

}

Binding to the Employee collection

Now you can use the collection and bind to the grid. Using a windows form, here is the code to add an employee to the grid and also to the employee collection:

private void btnAddToGrid_Click(object sender, System.EventArgs e)

{

                  Employee Employee = new Employee();

                  Employee.FirstName = txtFirstName.Text;

                  Employee.LastName = txtLastName.Text;

                  Employee.EmployeeNumber = Convert.ToInt32(txtEmployeeNumber.Text);

                  EmployeeCollection.Add(Employee);

                  //Bind to grid here.

                  dataGrid1.DataSource = EmployeeCollection;

                  CurrencyManager cm =

                        (CurrencyManager) this.dataGrid1.BindingContext[EmployeeCollection];

                  if (cm != null)

                  {

                        cm.Refresh();

                  }

            }

Here is the code to remove the employee object from the grid and also from the employee collection:

                        private void btnRemoveFromGrid_Click(object sender, System.EventArgs e)

            {                       EmployeeCollection.RemoveAt(dataGrid1.CurrentCell.RowNumber);

                  //Bind to grid here.

                  dataGrid1.DataSource = EmployeeCollection;

                  CurrencyManager cm =

                        (CurrencyManager) this.dataGrid1.BindingContext[EmployeeCollection];

                  if (cm != null)

                  {

                        cm.Refresh();

                  }

            }

A good article explaining the pros and cons of datasets can be found at:

http://msdn.microsoft.com/asp.net/default.aspx?pull=/library/en-us/dnaspp/html/CustEntCls.asp

Also the book Expert C# Business Objects goes into more depth than my code example and is a great read.

http://www.lhotka.net