The data source does not support server-side data paging

Question

I have a GridView on my screen and need it to allow paging.

Markup:

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" 
  AutoGenerateColumns="False" DataSourceID="ObjectDataSource1">
  <Columns>
    <asp:BoundField DataField="appID" HeaderText="appID" SortExpression="appID" />
  </Columns>
</asp:GridView>

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server" 
  SelectMethod="GetBookingId" 
  TypeName="AppointmentRepository">
  <SelectParameters>
    <asp:Parameter Name="maximumRows" Type="Int32" />
    <asp:Parameter Name="startRowIndex" Type="Int32" />
  </SelectParameters>
</asp:ObjectDataSource>

Code-behind:

ObjectDataSource1.SelectParameters["maximumRows"].DefaultValue = "10";
ObjectDataSource1.SelectParameters["startRowIndex"].DefaultValue = "0";

LINQ query:

public IQueryable<tblAppointment> GetBookingId(int maximumRows, int startRowIndex)
{
    var result = (FROM a IN dc.tblAppointments
                  SELECT a).Skip(startRowIndex).Take(maximumRows);
}

However I receive this error:

The data source does not support server-side data paging.

What am I doing wrong?

Solution 1

A simple ToList() on your result var should work.

Edit: As explained in comments below my answer, the reason for the error is that the data source should implement ICollection. IEnumerable does not, when you do ToList() it converts it into a list which implements ICollection.

Solution 2

You can use generic List<T> also. See the sample code snippet:

public List<Company> GetContactList(int startindex)
{

    string path = Server.MapPath("~/contacts.xml");
    XDocument xd = XDocument.Load(path);
    IEnumerable<Company> results = (from items in xd.Elements("Company").Elements("Contact")
                   select new Company
                   {
                       Id = items.Element("ID").Value,
                       Photo = (string)items.Element("photo").Value,
                       Name = (string)items.Element("Name").Value,
                       BloodGroup = (string)items.Element("Bg").Value,
                       Dob = (string)items.Element("dob").Value,
                       Anniversery = (string)items.Element("avd").Value,
                       Mobile = (string)items.Element("cnum").Value,
                       designation = (string)items.Element("desig").Value,
                       Team = (string)items.Element("team").Value
                   }).Skip(startindex*10).Take(10);
    return (List<Company>) results;
}

You can also use DataSet/DataTable instead of DataReader.

Solution 3

.ToList() at the end of the DataSource, I am assigning worked for me like below:

gvCaseLabelsLeft.DataSource = caseLabelsList.OrderBy(c=>c.caseLabelNumber).ToList();

Solution 4

I've changed my code to this:

public List<string> ListofNewsTitle()
{
    var query = from n in db.NewsEvents
                orderby n.NewsDate descending
                select n.NewsTitle;
    return query.ToList();        
}

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