class1.cs

来自DoFactory的设计模式, 由于是本人根据已有代码创建,没有NETOptimized项

// Template pattern -- Real World example  

using System;
using System.Data;
using System.Data.OleDb;

namespace DoFactory.GangOfFour.Template.RealWorld
{

    // MainApp test application 

    class MainApp
    {
        static void Main()
        {
            DataAccessObject dao;

            dao = new Categories();
            dao.Run();

            dao = new Products();
            dao.Run();

            // Wait for user 
            Console.Read();
        }
    }

    // "AbstractClass" 

    abstract class DataAccessObject
    {
        protected string connectionString;

        protected DataSet dataSet;

        public virtual void Connect()
        {
            // Make sure mdb is on c:\ 
            connectionString =
              "provider=Microsoft.JET.OLEDB.4.0; " +
              "data source=c:\\nwind.mdb";
        }

        public abstract void Select();
        public abstract void Process();

        public virtual void Disconnect()
        {
            connectionString = "";
        }

        // The "Template Method" 

        public void Run()
        {
            Connect();
            Select();
            Process();
            Disconnect();
        }
    }

    // "ConcreteClass" 

    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();
        }
    }

    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();
        }
    }
}