3 Tier Architecture Using ASP.NET

one representing the customer type and anotehr representing the customer itself.

public class ClsCustomerType
{
public ClsCustomerType(int id)
{
this.Id = id;
switch(Id)
{
case 0:
this.Name = "--Select--";
break;
case 1:
this.Name = "Gold";
break;
case 2:
this.Name = "Silver";
break;
case 3:
this.Name = "Normal";
break;
}
}
public int Id
{
get;
set;
}
public string Name
{
get;
set;
}
}
public class ClsCustomer
{
public string CustomerCode
{
get;
set;
}
public string CustomerName
{
get;
set;
}
public ClsCustomerType CustomerType
{
get;
set;
}
}
}

Step 2: Create Business Access Layer

public class ClsCustomerBAL
{
public List<ClsCustomerType> LoadCustomerTypes()
{
return new List<ClsCustomerType>()
{
new ClsCustomerType(0),new ClsCustomerType(1),new ClsCustomerType(2),new ClsCustomerType(3)
};
}
public IEnumerable<ClsCustomer> LoadCustomers()
{
DataTable dtCustomer=new ClsCustomerDAL().LoadCustomers();
}
public void SaveRecord(ClsCustomer objCustomer)
{
new ClsCustomerDAL().SaveRecord(objCustomer);
}
public ValidationResult ValidateCustomerCode(string strPriCustomerCode)
{
if(strPriCustomerCode.Trim() == string.Empty)
{
return ValidationResult.Empty;
}
else if(strPriCustomerCode.Trim().Length < 5)
{
return ValidationResult.InValid;
}
return ValidationResult.Valid;
}
}

Step 3: Next we need a Data Access Layer:

using System.Data;
using System.Data.SqlClient;
using Entities;
namespace DAL
{
public class ClsCustomerDAL
{
private const string ConnectionString = @"Data Source=SUKESH-PC\S2;Initial Catalog=3LayerApp;Persist
Security Info=True;User ID=sa;Password=aa";
public DataTable LoadCustomers()
{
//Load Data From Database
}
public void SaveRecord(ClsCustomer objCustomer)
{
//Save Data Into Database
}
}
}

Step 4: That's it; now the only thing remaining is creation of the UI:



In the UI the code behind we will just call the functions created on BAL, there will not be any database logic, and neither wll there be validation logic.

Hope this explanation was enough to understand, how to create a simple 3-Layer application using ASP.Net also I hope you enjoyed reading this article.

Please download the source code to better understand the functionality.

Make sure to put some good comments.