DataTable中删除一行后，使用SqlDataAdapter.Update(DataTable)无效，请教

Question

DataTable中删除一行后，使用SqlDataAdapter.Update(DataTable)无效，请教，下面贴出代码

    /// <summary>
    /// 将数据保存到数据库
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnSave_Click(object sender, EventArgs e)
    {
      Save();
    }

    /// <summary>
    /// 保存数据
    /// </summary>
    private void Save()
    {
      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        SqlDataAdapter dap = CreateCustomerAdapter(connection);
        DataTable dt = (DataTable)gvwEmp.DataSource;
        dap.Update(dt);
      }
    }

    /// <summary>
    /// 构造SqlDataAdapter
    /// </summary>
    /// <param name="connection"></param>
    /// <returns></returns>
    public static SqlDataAdapter CreateCustomerAdapter(SqlConnection connection)
    {
      SqlDataAdapter dap = new SqlDataAdapter();

      //Select
      SqlCommand command = new SqlCommand("SELECT * FROM Customers", connection);
      dap.SelectCommand = command;

      //Insert
      command = new SqlCommand("INSERT INTO Customers (序号,内容) VALUES (@序号, @内容)", connection);
      command.Parameters.Add("@序号", SqlDbType.Int, 4, "序号");
      command.Parameters.Add("@内容", SqlDbType.NVarChar, 300, "内容");
      dap.InsertCommand = command;

      //Update
      command = new SqlCommand("UPDATE Customers SET 序号 = @序号, 内容 = @内容 WHERE ID = @ID", connection);
      command.Parameters.Add("@序号", SqlDbType.Int, 4, "序号");
      command.Parameters.Add("@内容", SqlDbType.NVarChar, 300, "内容");
      SqlParameter parameter = command.Parameters.Add("@ID", SqlDbType.Int, 4, "ID");
      parameter.SourceVersion = DataRowVersion.Original;
      dap.UpdateCommand = command;

      //Delete
      command = new SqlCommand("DELETE FROM Customers WHERE ID = @ID", connection);
      parameter = command.Parameters.Add("@ID", SqlDbType.Int, 4, "ID");
      parameter.SourceVersion = DataRowVersion.Original;
      dap.DeleteCommand = command;

      return dap;
    }