使用 Enterprise library 2.0 DAAB

最近在学习Enterprise Library，按照 Enterprise Library 2.0 Data Access Application Block By David Hayden的例子做了一个

另外还发现VS设计器设计好界面，先后修改InitialComponent中的代码，如果再进行界面的更改，IntialComponent中的会自动初始化，也就是不保留更改部分的代码。
所以在改好DataGridView的AutoGenerateColumns 为true，又进行界面设计会导致AutoGenerateColumns为false

下面是我的关键代码
DataSet GetOrdersByCustomerId（string customerId) 和 DataTable GetCategories()

  public class SampleDataAccess
    {
        public static DataSet GetOrdersByCustomerId(string customerId)
        {
            // create database from default config
            Database northwind = DatabaseFactory.CreateDatabase();

            // get db command from northwind database
            DbCommand cmd = northwind.GetSqlStringCommand("SELECT OrderId,OrderDate FROM Orders WHERE CustomerID = @CustomerID");

            // add customer id paramter to db command
            northwind.AddInParameter(cmd, "@CustomerID", DbType.String, customerId);

            // order dataset
            DataSet dsOrders = new DataSet();

            // load order data set
            northwind.LoadDataSet(cmd, dsOrders, "Orders");

            return dsOrders;
        }

        public static DataTable GetCategories()
        {
            Database northwind = DatabaseFactory.CreateDatabase();
            DbCommand command = northwind.GetSqlStringCommand("SELECT * FROM Categories");

            DataTable categories = new DataTable();
            using (IDataReader dr = northwind.ExecuteReader(command))
            {
                categories.Load(dr);
            }

            return categories;
        }

    }

界面处理

public partial class GetOrdersByCustomerIdSample : Form
    {
        public GetOrdersByCustomerIdSample()
        {
            InitializeComponent();
            // intialize data grid view for orders
            InitializeDataGridView();
        }

        private void btnGetOrdersByCustomerId_Click(object sender, EventArgs e)
        {
            string customerId = GetCustomerId();
            bindingSource1.DataSource = SampleDataAccess.GetOrdersByCustomerId(customerId);
            dataGridView1.DataSource = bindingSource1;
        }

        private void InitializeDataGridView()
        {
            dataGridView1.AutoGenerateColumns = true;

        }

        private string GetCustomerId()
        {
            // retrieve customer id from form
            string customerId = "VINET";
            return customerId;
        }
    }

源文件