如何在不使用asp.net的会话的情况下将选定的数据（数据列表）从一页转移到另一页？

Question

I have used two pages. First one is parent page and second one is popup page. I want to retrieve selected data from popup page to parent page. currently I am using session for it but I want to do it without session.

Popup page Code is as below:

List<vw_ServiceandProduct> lstsapm = new List<vw_ServiceandProduct>();

lstsapm = (from a in db.vw_ServiceandProduct where a.IsActive == true && a.BranchID == Common.BranchID select a).ToList();

Session["lstsapmsession"] = lstsapm;

Parent page Code is as below :

List<vw_ServiceandProduct> lstsapm = Session["lstsapmsession"] as List<vw_ServiceandProduct>;

GridView1.DataSource = lstsapm;
GridView1.DataBind();

Answer 1

Since you mentioned memory usage, I'd recommend using cross page postback (cookie & query string can handle only so many data). With this method you essentially persist your data into view state (which is implemented as hidden field) and use http post method to get around - sending the viewstate along.

Example:

public interface ITransferSomething {
  // anything here as long as it is decorated with [Serializable]
  IList<vw_ServiceandProduct> SerializableValue { get; }
  // exposing standard property of System.Web.UI.Page
  bool IsCrossPagePostBack { get; }
}  

Default.aspx

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
  <asp:LinkButton PostBackUrl="~/Default2.aspx" Text="Transfer!" runat="server" />
</asp:Content>    

Default.aspx.cs

public partial class _Default : System.Web.UI.Page, ITransferSomething {
  protected void Page_Load(object sender, EventArgs e) {
    if (!IsPostBack) {
      SerializableValue = new List<vw_ServiceandProduct> {
        new vw_ServiceandProduct { Name = "foo" }
      };
    }
  }

  public IList<vw_ServiceandProduct> SerializableValue {
    get { return (IList<vw_ServiceandProduct>)ViewState["SerializableValue"]; }
    set { ViewState["SerializableValue"] = value; }
  }
} 

Default2.aspx.cs

public partial class Default2 : System.Web.UI.Page {
  protected void Page_Load(object sender, EventArgs e) {
    var transfer = Page.PreviousPage as ITransferSomething;
    if (transfer != null && transfer.IsCrossPagePostBack) {
      SerializableValue = transfer.SerializableValue;
    }
  }

  public IList<vw_ServiceandProduct> SerializableValue {
    get { return (IList<vw_ServiceandProduct>)ViewState["SerializableValue"]; }
    set { ViewState["SerializableValue"] = value; }
  }
}

Answer 2

The method I described in the comment would work like this:

List<vw_ServiceandProduct> lstsapm = new List<vw_ServiceandProduct>();
lstsapm = (from a in db.vw_ServiceandProduct where a.IsActive == true && a.BranchID == Common.BranchID select a).ToList();
//Session["lstsapmsession"] = lstsapm;
string key = Guid.NewGuid().ToString("N");
string path = Server.MapPath("~/App_Data/TempFiles/" + key);
DataContractSerializer dcs = new DataContractSerializer(typeof(List<vw_ServiceandProduct>));
using (var outStream = File.OpenWrite(path))
{
    using (XmlDictionaryWriter xdw = XmlDictionaryWriter.CreateTextWriter(outStream, Encoding.UTF8))
    {
        dcs.WriteObject(xdw, lstsapm);
    }
}

// pass key to parent using querystring or cookie


// Parent page Code:
string key = ""; // from cookie or querystring
List<vw_ServiceandProduct> lstsapm = null; //Session["lstsapmsession"] as List<vw_ServiceandProduct>;
string path = Server.MapPath("~/App_Data/TempFiles/" + key);
DataContractSerializer dcs = new DataContractSerializer(typeof(List<vw_ServiceandProduct>));
using (var inStream = File.OpenRead(path))
{
    using (XmlDictionaryReader xdr = XmlDictionaryReader.CreateTextReader(inStream, new XmlDictionaryReaderQuotas()))
    {
        lstsapm = dcs.ReadObject(xdr) as List<vw_ServiceandProduct>;
    }
}
if (lstsapm != null)
{
    GridView1.DataSource = lstsapm;
    GridView1.DataBind();
}