Create a gift card payment provider

public class GiftGateway : IPaymentGateway
       {
         IDictionary<string, string> _configData;
     
         public bool ProcessPayment(Payment payment, ref string message)
           {
             OtherPayment p = (OtherPayment)payment;
             if (!String.IsNullOrEmpty(p.ValidationCode))
               {
                 GiftManager.DeactivateGiftCard(Settings["GiftCardMetaClass"], PrimaryKeyId.Parse(p.ValidationCode));
                 p.Status = "Processed";
               }
             return true;
           }
     
         /// <summary>
         /// Returns the configuration data associated with a gateway.
         /// Sets the configuration gateway data. This data typically includes
         /// information like gateway URL, account info and so on.
         /// </summary>
         /// <value>The settings.</value>
         /// <returns></returns>
         public virtual IDictionary<string, string> Settings
           {
             get
               {
                 return _configData;
               }
             set
               {
                 _configData = value;
               }
           }
       }

public static class GiftManager
       {
         public const string ContactIdFieldName = "ContactId";
         public const string AmountFieldName = "Amount";
         public const string BalanceFieldName = "Balance";
         public const string ContactFieldName = "Contact";
         public const string IsActiveFieldName = "IsActive";
         public const string RedemptionCodeFieldName = "RedemptionCode";
         public const string TitleFieldName = "Title";
     
         public static EntityObject[] GetClientGiftCards(string giftCardMetaClass, PrimaryKeyId contactId)
           {
             return BusinessManager.List(giftCardMetaClass,
               new FilterElement[]
                 {
                   FilterElement.EqualElement(ContactIdFieldName, contactId),
                   FilterElement.EqualElement(IsActiveFieldName, true)
                 });
           }
     
         public static void DeactivateGiftCard(string giftCardMetaClass, PrimaryKeyId giftCardId)
           {
             // Load Gift Card
             EntityObject giftCard = BusinessManager.Load(giftCardMetaClass, giftCardId);
             // Update field
             giftCard[IsActiveFieldName] = false;
             // Save Changes
             BusinessManager.Update(giftCard);
           }
       }

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="ConfigurePayment.ascx.cs"Inherits="GiftCardPaymentProvider.ConfigurePayment" %><div id="DataForm">
              <table cellpadding="0" cellspacing="2">     <tr>      <td class="FormLabelCell" colspan="2"><b>Configure Gift Card</b></td>    </tr>
              </table>  <br />  <table class="DataForm">    <tr>      <td class="FormLabelCell"><asp:Literal ID="Literal4" runat="server" Text="MetaClass name" />:</td>      <td class="FormFieldCell">
                    <asp:TextBox 
                      Runat="server" 
                      ID="MetaClassName" 
                      Width="230">
                    </asp:TextBox>
                    <br />
                    <asp:RequiredFieldValidator 
                      ControlToValidate="MetaClassName" 
                      Display="dynamic" 
                      Font-Name="verdana" 
                      Font-Size="9pt" 
                      ErrorMessage="'MetaClass name' must not be left blank."
                      runat="server" 
                      id="RequiredFieldValidator2">
                    </asp:RequiredFieldValidator>
                  </td>
                </tr>  </table></div>

public partial class ConfigurePayment : System.Web.UI.UserControl, IGatewayControl
      {
        string _validationGroup = string.Empty;
        private PaymentMethodDto _paymentMethodDto = null;
        private const string _metaClassParameterName = "GiftCardMetaClass";
    
        /// <summary>
        /// Handles the Load event of the Page control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>
        protected void Page_Load(object sender, System.EventArgs e)
          {
            BindData();
          }
    
        /// <summary>
        /// Binds a data source to the invoked server control and all its child controls.
        /// </summary>
        public override void DataBind()
          {
            BindData();
            base.DataBind();
          }
    
        /// <summary>
        /// Binds the data.
        /// </summary>
        public void BindData()
          {
            // fill in the form fields
            if (_paymentMethodDto != null && _paymentMethodDto.PaymentMethodParameter != null)
              {
                var param = GetParameterByName(_metaClassParameterName);
                if (param != null)
                  {
                    MetaClassName.Text = param.Value;
                  }
              }
            else
              {
                this.Visible = false;
              }
          }
    
        /// <summary>
        /// Saves the object changes.
        /// </summary>
        /// <param name="dto">The dto.</param>
        public void SaveChanges(object dto)
          {
            if (this.Visible)
              {
                _paymentMethodDto = dto as PaymentMethodDto;
                if (_paymentMethodDto != null && _paymentMethodDto.PaymentMethodParameter != null)
                  {
                    var paymentMethodId = Guid.Empty;
                    if (_paymentMethodDto.PaymentMethod.Count > 0)
                      {
                        paymentMethodId = _paymentMethodDto.PaymentMethod[0].PaymentMethodId;
                      }
    
                    var param = GetParameterByName(_metaClassParameterName);
                    if (param != null)
                      {
                        param.Value = MetaClassName.Text;
                      }
                    else
                      {
                        CreateParameter(_paymentMethodDto, _metaClassParameterName, MetaClassName.Text, paymentMethodId);
                      }
                  }
              }
          }
    
        /// <summary>
        /// Gets the name of the parameter by.
        /// </summary>
        /// <param name="name">The name.</param>
        private PaymentMethodDto.PaymentMethodParameterRow GetParameterByName(string name)
          {
            var rows = (PaymentMethodDto.PaymentMethodParameterRow[])_paymentMethodDto.PaymentMethodParameter.Select(String.Format("Parameter = '{0}'", name));
            if (rows != null && rows.Length > 0)
              {
                return rows[0];
              }
            else 
              {
                return null;
              }
          }
    
        /// <summary>
        /// Creates the parameter.
        /// </summary>
        /// <param name="dto">The dto.</param>
        /// <param name="name">The name.</param>
        /// <param name="value">The value.</param>
        /// <param name="paymentMethodId">The payment method id.</param>
        private void CreateParameter(PaymentMethodDto dto,
            string name, string value, Guid paymentMethodId)
          {
            var newRow = dto.PaymentMethodParameter.NewPaymentMethodParameterRow();
            newRow.PaymentMethodId = paymentMethodId;
            newRow.Parameter = name;
            newRow.Value = value;
            // add the row to the dtoif (newRow.RowState == DataRowState.Detached)
            dto.PaymentMethodParameter.Rows.Add(newRow);
          }
    
        /// <summary>
        /// Loads the object.
        /// </summary>
        /// <param name="dto">The dto.</param>
        public void LoadObject(object dto)
          {
            _paymentMethodDto = dto as PaymentMethodDto;
          }
    
        /// <summary>
        /// Gets or sets the validation group.
        /// </summary>
        public string ValidationGroup
          {
            get
              {
                return _validationGroup;
              }
            set
              {
                _validationGroup = value;
              }
          }
      }