using System;
using System.Data;
using System.Data.OleDb;
namespace DoFactory.GangOfFour.Template.RealWorld
{
/// <summary>
/// MainApp startup class for Real-World
/// Template Design Pattern.
/// </summary>
class MainApp
{
/// <summary>
/// Entry point into console application.
/// </summary>
static void Main()
{
DataAccessObject daoCategories = new Categories();
daoCategories.Run();
DataAccessObject daoProducts = new Products();
daoProducts.Run();
// Wait for user
Console.ReadKey();
}
}
/// <summary>
/// The 'AbstractClass' abstract class
/// </summary>
abstract class DataAccessObject
{
protected string connectionString;
protected DataSet dataSet;
public virtual void Connect()
{
// Make sure mdb is available to app
connectionString =
"provider=Microsoft.JET.OLEDB.4.0; " +
"data source=..\\..\\..\\db1.mdb";
}
public abstract void Select();
public abstract void Process();
public virtual void Disconnect()
{
connectionString = "";
}
// The 'Template Method'
public void Run()
{
Connect();
Select();
Process();
Disconnect();
}
}
/// <summary>
/// A 'ConcreteClass' class
/// </summary>
class Categories : DataAccessObject
{
public override void Select()
{
string sql = "select CategoryName from Categories";
OleDbDataAdapter dataAdapter = new OleDbDataAdapter(
sql, connectionString);
dataSet = new DataSet();
dataAdapter.Fill(dataSet, "Categories");
}
public override void Process()
{
Console.WriteLine("Categories ---- ");
DataTable dataTable = dataSet.Tables["Categories"];
foreach (DataRow row in dataTable.Rows)
{
Console.WriteLine(row["CategoryName"]);
}
Console.WriteLine();
}
}
/// <summary>
/// A 'ConcreteClass' class
/// </summary>
class Products : DataAccessObject
{
public override void Select()
{
string sql = "select ProductName from Products";
OleDbDataAdapter dataAdapter = new OleDbDataAdapter(
sql, connectionString);
dataSet = new DataSet();
dataAdapter.Fill(dataSet, "Products");
}
public override void Process()
{
Console.WriteLine("Products ---- ");
DataTable dataTable = dataSet.Tables["Products"];
foreach (DataRow row in dataTable.Rows)
{
Console.WriteLine(row["ProductName"]);
}
Console.WriteLine();
}
}
}