Question

I’m returning a list like this from three lists of objects * thanks to @sehe

        `var joined = from p in personList
         join par in relations
             on p.Id equals par.PersonId
         join a in addressList
             on a.Id equals par.AddressId
         select new { Person = p, Address = a };`

How do I set joined as a datasource for a listview and access the properties in the aspx page?

Okay here’s some more code maybe that will help since I’m getting two different answers on this.

// the code behind

    protected void Page_Init(object sender, EventArgs e)
{
    List<Customer> customers = Customer.GetAllCustomers();
    List<Address> addresses = Address.GetAllAddresses();
    List<AddressRelation> addressRelations = AddressRelation.GetAllAddressRelations();
    var results = from c in customers
                  join rel in addressRelations
                  on c.CustomerID equals rel.CustomerID
                  join a in addresses
                  on rel.CustomerAddressID equals a.CustomerAddressID

                  select new
                  {
                      FirstName = c.FirstName,
                      LastName = c.LastName,
                      PhoneNumber = c.PhoneNumber,
                      AddressLine = a.AddressLine1,
                      CustomerCity = a.City,
                      CustomerZip = a.ZipCode
                  };

    ListView1.DataSource = results;
    ListView1.DataBind();

Here’s my listview:

            `<asp:ListView ID="ListView1" runat="server" >`
            `<LayoutTemplate>`
             <ul style="float:left; width:250px">
             <asp:PlaceHolder ID="itemPlaceHolder" runat="server"></asp:PlaceHolder>
             </ul>
             </LayoutTemplate>
             <ItemTemplate>
             <li><%# Eval("FirstName") %></li>
             <li><%# Eval("AddressLine") %></li>
             </ItemTemplate>
             <ItemSeparatorTemplate><hr /></ItemSeparatorTemplate>
             </asp:ListView>

Answer 1

Two problems here:

You haven’t fully enumerated the set yet – you should probably call an aggregator like .ToList() or .ToArray().

In addition, you’re creating an anonymous object as your result. Outside the specific scope of that code, nothing has any idea what properties that object contains. You should switch to a pre defined class that has known properties if you want to use that object elsewhere.