My name
is
Jon Skeet

Linqtoxml filtering not working

I am fallowing a tutorial on the internet I use xml file this .I think missed out something .Because Nothing happens Just a blank page appears.What I am doing wrong again.How can i bind filtered data to gridview

protected void Page_Load(object sender, EventArgs e)
{
    XElement root = XElement.Load(Server.MapPath("PurchaseOrders.xml"));
    IEnumerable<XElement> purchaseOrders =
        from el in root.Elements("PurchaseOrder")
        where
            (from add in el.Elements("Address")
             where
                 (string)add.Attribute("Type") == "Shipping" &&
                 (string)add.Element("State") == "NY"
             select add)
            .Any()
        select el;
    foreach (XElement el in purchaseOrders)
    {
        GridView1.DataSource = el;
    }
    GridView1.DataBind();
}

You're currently looking for elements in the unnamed namespace - whereas the file you've linked to has a namespace URI of "http://www.adventure-works.com" for the elements you're looking for.

Just use:

XNamespace aw = "http://www.adventure-works.com";
IEnumerable<XElement> purchaseOrders =
from el in root.Elements(aw + "PurchaseOrder")
where
    (from add in el.Elements(aw + "Address")
     where
         (string)add.Attribute("Type") == "Shipping" &&
         (string)add.Element(aw + "State") == "NY"
     select add)
    .Any()
select el;

Or slightly more simply, IMO:

XNamespace aw = "http://www.adventure-works.com";
IEnumerable<XElement> purchaseOrders =
    root.Elements(aw + "PurchaseOrder")
        .Where(order => order.Elements(aw + "Address")
                 .Any(add => (string) add.Attribute(aw + "Type") == "Shipping"
                          && (string) add.Element(aw + "State") == "NY"));

(Basically this doesn't use query expressions because they're not actually helping you here, and I'm using the Any overload which takes a predicate...)

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