c#datagridview更改未反映在基础绑定源中

EDIT：我使用的是绑定到下面BindingSource的DataGridView，但是当我在DataGridView中编辑单元格时，检查BindingSource.CurrentItemChanged会显示该单元格的原始值。我是否错误地使用了BindingSource？我认为重点是它将反映绑定控件所做的更改。下面列出了我的代码，如果有任何帮助，我们将不胜感激！

using System;
using System.Windows.Forms;
using System.Drawing;
public class GuiProductMaintenanceForm : Form {
    private const int FORM_HEIGHT = 600;
    private const int FORM_WIDTH = 800;
    private BindingNavigator menu;
    private DataGridView grid;
    private BindingSource source;
    public GuiProductMaintenanceForm() {
        instComponents();
        posComponents();
        setProperties();
        addComponents();
    }
    private void instComponents() {
        this.source = new BindingSource(
            DataHandler.getProductData(), "Products");
        this.menu = new BindingNavigator(source);
        this.grid = new DataGridView();
    }
    private void posComponents() {
        int xPos = 0;
        int yPos = 0;
        this.menu.Location = new Point(xPos, yPos);
        this.grid.Location = new Point(xPos, yPos + this.menu.Height);
    }
   private void setProperties() {
        //controls
        this.menu.Size = new Size(FORM_WIDTH, 32);
        this.grid.Size = new Size(FORM_WIDTH, FORM_HEIGHT - this.menu.Height);
        this.grid.BorderStyle = BorderStyle.FixedSingle;
        this.grid.DataSource = source;
        this.grid.AllowUserToAddRows = false;
        this.grid.ReadOnly = false;
        this.grid.DefaultCellStyle.Font = new Font(
            FontFamily.GenericSansSerif, 12);
        //this form
        this.Text = "Product Maintenance";
        this.ClientSize = new Size(FORM_WIDTH, FORM_HEIGHT);
        this.FormBorderStyle = FormBorderStyle.FixedSingle;
    }
    private void addComponents() {
        this.Controls.Add(this.menu);
        this.Controls.Add(this.grid);
    }
}

GetProductData（）只是返回一个包含数据的DataSet，但为了安全起见，我将包含代码。

public static DataSet getProductData() {
        MySqlConnection c = makeConnection(getDefaultConnStr());
        c.Open();
        string selectStatement = "SELECT * FROM Products";
        MySqlDataAdapter da = new MySqlDataAdapter(selectStatement, c); 
        DataSet ds = new DataSet();
        da.Fill(ds, "Products");
        return ds; 
}