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Repeater pulling as Null is code behind?

I have a repeater for Frequently asked questions on a Website that I'm trying to get separated into categories depending on which treeid it is related to.
When I reference the repeater (rp_FAQ) in the code behind to check if it is null so I can pass the category id to the stored procedure it keeps returning null when I need the item to exist when check that it's null.
I can't seem to find the route of the problem so as second set of eyes would be really grateful.
Thanks.
I have this repeater:
<asp:Repeater ID="rp_FAQ" DataSourceID="DS_GetFAQs" runat="server" OnItemDataBound="rp_FAQCategories_ItemDataBound">
<HeaderTemplate>
<div class="container-full fares_container">
<div class="row">
</HeaderTemplate>
<ItemTemplate>
<dt>Q: <%# Eval("Question") %></dt>
<dd>A: <%# Eval("Answer") %></dd>
</ItemTemplate>
<FooterTemplate>
</dl>
</div>
</div>
</FooterTemplate>
</asp:Repeater>
Here is my code behind:
protected void rp_FAQCategories_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
Repeater rp_FAQRep = e.Item.FindControl("rp_FAQ") as Repeater;
if (rp_FAQRep != null)
{
if (TreeData.CurrentDefault.IsRelation(Convert.ToInt32(Resources.Pages.FAQ)))
{
DS_GetFAQs.SelectParameters["CategoryID"].DefaultValue = "1";
}
rp_FAQRep.DataSource = DS_GetFAQs;
rp_FAQRep.DataBind();
}
}

The FindControl method is only needed if you are trying to get a reference to a control which is inside the control which raised the event (in this case ItemDataBound). So you can either reference the control directly if it's not nested inside another control or use sender. For example:
var rp_FAQRep = rp_FAQ; //A bit pointless but demonstrates the point
or
var rp_FAQRep = (Repeater)sender;

The problem is that you are trying to find the rp_FAQ control in a control inside rp_FAQ itself.
Since e.Item is the RepeatItem under rp_FAQ, you can just cast e.Item.Parent, or sender if you will.

e.Item is the RepeaterItem within the Repeater - it does not contain the Repeater itself. Just cast the sender of the event:
var rp_FAQRep = (Repeater)sender;

Update value in ListView

I have a button inside a listview and a label. The label is bound to my database and displays a score. If you press the button I want the score to update on client side. But Since I cant access items in Listview from codebehind I have no idea how to do this. And updatepanel does not work.
My listview bound to a Sqldatasource:
<asp:ListView ID="ListViewSearch" runat="server" DataSourceID="SqlDataSourceWebsite" DataKeyNames="WebsiteID">
My buttons and my label for rating:
<asp:LinkButton ID="BtnUp" runat="server" CssClass="btn btn-default btn-xs" CommandArgument='<%# Eval("testId").ToString() %>' OnClick="up_click"></asp:LinkButton>
<asp:LinkButton ID="BtnDown" runat="server" CssClass="btn btn-default btn-xs" CommandArgument='<%# Eval("testId").ToString() %>' OnCommand="down_click"></asp:LinkButton>
<asp:Label ID="LabelRating" runat="server" Text=' <%# Eval("rating") %>'></asp:Label>
upClick() function:
protected void up_click(object sender, EventArgs e)
{
LinkButton btn = (LinkButton)sender;
String webID = btn.CommandArgument.ToString();
int ID = Convert.ToInt32(webID);
click(ID, 1);
}
Click() function:
public void click(int webID, int vote)
{
using (SqlConnection con = new SqlConnection(strCon))
{
using (SqlCommand cmd = con.CreateCommand())
{
cmd.CommandText = "UPDATE [Test] SET [rating]+=#vote WHERE [testId]=#testID";
cmd.Parameters.AddWithValue("#webID", webID);
cmd.Parameters.AddWithValue("#vote", vote);
con.Open();
cmd.ExecuteNonQuery();
}
con.Close();
}
}
The code updates the rating as it is supposed to, but to see the change I have to refresh the page. So the questions is; How do I update a value inside a listview by clicking a button inside that same lisview?
(If this is not possible, please suggest a different way that I can display results from a search in a list that offers the same customization.)

I'm more into ASP MVC however maybe my tip will help you.
The way I did these behaviors was to bind javascript function to the button and using jQuery I've send 'GET' request to the specific action(method) on the server for example: www.myexample.com/getData?tableid=24 which responds with json containing needed data.
Hope this will direct you to proper solution.
Cheers,
Marek

Displaying photo from photopath in eval repeater ASP.NET

I am trying to display images in eval repeater but it doesn't work. When I put simply div instead of asp:Repeater I get the image path. (I have no problem with SQL side)
Can anyone tell what's wrong with this code?
Thanks.
<div class="wrapper">
<asp:Repeater runat="server" ID="Repeater1">
<ItemTemplate>
<asp:Image ID="Image1" ImageUrl="<%# Eval("PresidentPhotoPath") %>" runat="server" />
</ItemTemplate>
</asp:Repeater>
</div>
SqlConnection cnn = new SqlConnection("Initial Catalog=whitehouse;Data Source=localhost;Integrated Security=SSPI;");
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
cnn.Open();
SqlCommand cmd = new SqlCommand("SELECT PresidentPhotoPath FROM presidents", cnn);
SqlDataReader dr = cmd.ExecuteReader();
Repeater1.DataSource = dr;
Repeater1.DataBind();
cnn.Close();
}
}

The ImageUrl syntax here is wrong:
ImageUrl="<%# Eval("PresidentPhotoPath") %> "
You have double quotes inside of double quotes, change the outer quotes to be single quotes, like this:
ImageUrl='<%# Eval("PresidentPhotoPath") %>'
As for your issue with prepending Images/ before the file name, I would recommend using a code-behind method to build the string for you, like this:
protected string BuildPath(string photoPath)
{
return "Images/ + photoPath;
}
Note: Consider naming this something more useful than BuildPath as that is fairly generic, just picked that name because nothing better came to mind immediately.
Now in your markup you can just call the method, like this:
ImageUrl='<%# BuildPath(Eval("PresidentPhotoPath")) %>'
I recommend this approach for the following reasons:
The markup does not contain any complex logic whatsoever, just a method call with the Eval() value
It is easier to debug the logic versus embedded code blocks
You can leverage the power of Visual Studio compiler to catch syntax errors at compile-time versus run-time errors when the logic is embedded into the binding syntax of the markup

How to use Server Side variables on Markup

I want to use Session variable's value on the markup. This is the code written on UserContorl.ascx, file on NavigateUrl I want to send the Username which is stored in the session variable. I don't want to set NavigateUrl value on PageLoad function for some reason.
Note the code gives the error: The server tag is not well formed.
<asp:Panel ID="pnlMenuItems" runat="server" HorizontalAlign="Left">
<asp:HyperLink ID="LinkLogout" runat="server" NavigateUrl="~/logout/"+
<%= HttpContext.Current.Session["UserName"].ToString(); %>> CssClass="pnlMenuItems"
ForeColor="#666666">Logout</asp:HyperLink>
</asp:Panel>

You can bind data within server tags. e.g.
<asp:HyperLink ID="LinkLogout" runat="server"
NavigateUrl="<%# LogoutUrl %>"
CssClass="pnlMenuItems"
ForeColor="#666666">Logout</asp:HyperLink>
then in your code behind:
protected string LogoutUrl {
get {
return "~/logout/" + HttpContext.Current.Session["UserName"].ToString();
}
}
protected void Page_Load(object sender, EventArgs e) {
if(!IsPostBack) { DataBind(); }
}
The NavigateUrl gets set during the call to DataBind() using this method. In my example, the value would get set during page load, but you wouldn't have to specifically do it. If you need it to happen at a different time during the page lifecycle, you can try calling DataBind() during a different event.

How about:
<asp:Panel ID="pnlMenuItems" runat="server" HorizontalAlign="Left">
<asp:HyperLink ID="LinkLogout" runat="server"
NavigateUrl="<%# "~/logout/" + HttpContext.Current.Session["UserName"].ToString() %>"
CssClass="pnlMenuItems"
ForeColor="#666666">Logout</asp:HyperLink>
</asp:Panel>

Firing different linkbuttons in a Repeater and saving the value of each in an arraylist

Im using a repeater to display some products in an online shop for a school project. This is how the front end looks with the repeater
<asp:Repeater ID="Repeater1" runat="server" OnItemCommand="rptList_ItemCommand">
<ItemTemplate>
<span style="float:left; padding:25px;" class="backgrnd">
<asp:ImageButton ID="imgProd" runat="server" style="width:150px; height:150px;" ImageUrl='<%# DataBinder.Eval(Container.DataItem, "productImg")%>' CommandArgument='<%# DataBinder.Eval(Container.DataItem, "productID")%>' CommandName="ViewIndividProd"/><br />
<p style="clear:left;">
<asp:Label ID="lbName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "productName")%>' /><br />
<asp:Label ID="lbUnitPrice" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "unitPrice")%>'/><br />
<asp:Label ID="lbRatings" runat="server" Text=''>Ratings</asp:Label><br />
<asp:LinkButton ID="linkCart" runat="server" CommandArgument='<%# DataBinder.Eval(Container.DataItem, "productID")%>' CommandName="AddToCart">Add to Cart</asp:LinkButton>
</p>
</span>
</ItemTemplate>
</asp:Repeater>
As you can see I've added on the OnItemCommand in the Repeater tag so that this is invoked whenever one of the buttons(image/link) is fired. That works perfectly fine for both commandname AddToCart and ViewIndividProd. However, i want to store the the productid of a specific item that was invoked by the particular button. In my case now, it only stores ONE productid in the arraylist at a time and 'forgets' the productid that was stored previously when another linkbutton is clicked.
Question How do i make it such that everytime a linkbutton in the repeater is fired, it remembers the productid pertaining to the linkbutton that was fired and save these ids into the arraylist?
This is how the back end looks
ArrayList cart = new ArrayList();
protected void rptList_ItemCommand(object sender, RepeaterCommandEventArgs e) {
if (e.CommandName == "ViewIndividProd") {
Session["productID"] = e.CommandArgument.ToString();
Response.Redirect("IndividProduct.aspx");
}
if (e.CommandName == "AddToCart") {
string prodid = e.CommandArgument.ToString();
cart.Add(prodid);
Session["ShoppingCart"] = cart;
Response.Redirect("IndividCat.aspx");
}
msg.Text = "Shopping cart: " + String.Join(",", cart.ToArray());
}
Your feedback would be much appreciated.

You need to understand the Asp.net Page life cycle.
A new instance of your Page object is created on every request.
Values from your input are populated into it.
Your array list is getting recreated every time.
If you want the values to persist, you will have to store your arraylist in the ViewState or the Session
Refer: How to: Save Values in View State
void Page_Load(object sender, EventArgs e)
{
if (ViewState["arrayListInViewState"] != null)
{
PageArrayList = (ArrayList)ViewState["arrayListInViewState"];
}
else
{
// ArrayList isn't in view state, so we need to create it from scratch.
PageArrayList = CreateArray();
}
// Code that uses PageArrayList.
}

We can store comma separated or JSON value in either Session or hidden variable (If you are on the same page and opening new page in different tab then we can use hidden variable also). So every time an button has been click we can append the product id.