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How to get the next and previous item in a ListView and find a label name

I have a button in a ListView that when its click it opens a modal with information relevant to the button that was clicked. I was able to get the index of the current listview item but I need to get the text from a label in both the previous item and next item. Heres what I have:
protected void List_ItemCommand(object sender, ListViewCommandEventArgs e)
{
ListViewDataItem dataItem = (ListViewDataItem)e.Item;
//Gets index of Listview
int DispalyIndex = e.Item.DisplayIndex;
int ItemIndex = e.Item.DataItemIndex;
Button index = (Button)dataItem.FindControl("TitleButton");
Label Name = (Label)dataItem.FindControl("LabelName");
}
I tried decrementing the index but no luck, anyone have an idea or a better solution? Thanks.
UPDATE
Heres my listviews, I use the first Listview to get the title and then the second to pull Jobs under the title. I bind both with a query using data bind
<asp:ListView ID="List" runat="server" OnItemCommand="List_ItemCommand" OnItemDataBound="List_ItemDataBound">
<LayoutTemplate>
<table>
<tr>
<asp:PlaceHolder ID="itemPlaceholder" runat="server"></asp:PlaceHolder>
</tr>
</table>
</LayoutTemplate>
<ItemTemplate>
<span class="label label-primary"><%# Eval("LabelName")%></span> <br />
<asp:ListView ID="JobList" runat="server" ItemPlaceholderID="JobPlaceHolder" OnItemDataBound="JobList_ItemDataBound">
<LayoutTemplate>
<asp:PlaceHolder runat="server" ID="JobPlaceHolder" />
</LayoutTemplate>
<ItemTemplate>
<br />
<asp:Button runat="server" ID="TitleButton" Text='<%# Eval("Job Title") %>' Font-Size="XX-Small" Font-Bold="true" CssClass="btn-xs btn-default" ClientIDMode="Static" OnClick="TitleButton_Click" />
</ItemTemplate>
<EmptyDataTemplate>
<br />
<b> <asp:Label runat="server" Text="There is no job for this Family and Level!" /></b>
</EmptyDataTemplate>

Try this
//null check before performing an operation, dataItem might be the first element in the page
//If so, prevItem will be null
var prevItem = List.Items[itemIndex - 1].FindControl("LabelName") as Label;
//null check before performing an operation, dataItem might be the last element in the page
//If so, nextItem will be null
var lastItem = List.Items[itemIndex + 1].FindControl("LabelName") as Label;

Label ASP not being set

I have a label that is dynamically generated via a repeater, rollNo is a label that's a part of the itemTemplate. When I check the value of l, it goes in the if block but l.Text is still empty. check.Text only returns "d". Why?
Label l = (Label)item.FindControl("rollNo");
TextBox t = (TextBox)item.FindControl("quiz1");
if (l != null)
{
string a = l.Text;
check.Text = "d"+a;
}

Your code sample isn't complete as it has no rollNo in it, but I can tell you something...
You are using repeater and with that using template...The id you use inside the template is never will be the run-time id of any of your controls! Think about it! Let say you assigned rollNo to one of the elements in the template and you have 10 rows to pass to the repeater. Are you expecting to have 10 controls with the the same id of rollNo?! I hope not!
For that reason FindControl will return nothing while using on id inside a template...
You have to rethink what do you want or use a different approach to find the controls (loop)...

Repeater Markup:
<asp:Repeater id="Repeater1" runat="server" OnItemCommand="Repeater1_ItemCommand">
<ItemTemplate>
<tr onclick="rowReturn(this)">
<td><asp:Label CssClass="form-control" runat="server" ID="rollNo"><%# DataBinder.Eval(Container.DataItem, "sid") %></asp:Label></td>
<td><asp:TextBox CssClass="form-control" runat="server" ID="quiz1" required></asp:TextBox></td>
<td><asp:TextBox CssClass="form-control" runat="server" ID="quiz2" required></asp:TextBox></td>
<td><asp:Button CssClass="btn btn-success btn-sm form-control" ID="add" CommandName="add" runat="server" Text="Add" CommandArgument='<%#DataBinder.Eval(Container.DataItem, "sid") %>' /></td>
</tr>
</ItemTemplate>
Code Behind:
TextBox t1;
TextBox t2;
string rollNumber, T1, T2;
if (e.CommandName == "add")
{
// get CommandArgument you have selected on the button
string roll = e.CommandArgument.ToString();
rollNumber = roll;
foreach (RepeaterItem item in Repeater1.Items)
{
t1 = (TextBox)item.FindControl("quiz1");
t2 = (TextBox)item.FindControl("quiz2");
T1 = t1.Text;
T2 = t2.Text;
//...DB code or any other code
}
}

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.

How to access a legend tag from code

I have the following data-bound repeater code :
<%--categories--%>
<asp:Repeater ID="CategoryRepeater" runat="server" OnItemDataBound="ItemBound">
<ItemTemplate>
<div class="groupbox">
<fieldset>
<legend><%# Container.DataItem %></legend>
<table>
<asp:Repeater ID="ItemRepeater" runat="server">
<ItemTemplate>
<tr>
<td>
<asp:CheckBox id="chkItem" runat="server" Text='<%# Eval("Text")%>' />
<asp:HiddenField id="pgNos" runat="server" Value='<%# Eval("PGNos")%>' />
<asp:Button ID="btnXRefs" Text="x-refs" runat="server" CssClass="xRefButton" OnClick="btnSelectXRefs_Click" />
</td>
</tr>
</ItemTemplate>
</asp:Repeater>
</table>
</fieldset>
</div>
</ItemTemplate>
</asp:Repeater>
There is a repeater inside a repeater. How do I access the text inside the legend (<legend><%# Container.DataItem %></legend>) from code?
I tried :
foreach (RepeaterItem cr in CategoryRepeater.Items)
{
string heading = (string) cr.DataItem; // returns null
}

Container.DataItem is a runtime alias for the DataItem for this specific item in the bound list. For a Repeater which displays 10 rows of data, this is one row from the datasource...Basically, it's a specific row and at runtime you can get the Property Values from this row
I saw your above Mark Up...Seems like you are missing to mention the property of Data-Bound type Class like below.
<%# ((Your Class Name)Container.DataItem).Class Property Name %>
There is a repeater inside a repeater. How do I access the text inside
the legend (<%# Container.DataItem %>) from code?
As told by phemt.latd, you can change the Legend tag into server side control like below.
<legend id="lg" runat="server">
<%# ((Your Class Name)Container.DataItem).Class Property Name %>
</legend>
Now, in the Item-Bound Data Event, Find the Legend Control.
protected void rpt_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
HtmlGenericControl ctl = (HtmlGenericControl)e.Item.FindControl("lg");
ctl.InnerText //This is what will give you the result.
}
}

The legend tag that you use is not visible on server side. Is a client control and not a server one.
Try with this:
<legend id="myLegend" runat="server"><%# Container.DataItem %></legend>
Then in codebehind:
protected void ItemBound(Object sender, RepeaterItemEventArgs e)
{
if (e.Item.DataItem == null) return;
HtmlGenerics body = (HtmlGenerics)e.Item.FindControl("myLegend");
body.InnerText = "Foo";
}

Target accordion pane content template after databind so that I can load data on demand?

I have an accordion that has another accordion inside one of its panes. This inner accordion is created using a datasource so each of its panes are loaded from a list of objects. In this particular case, this datasource is also loaded on demand. Now, where I'm stuck is that I want to be able to load the pane headers only and then load the contents when the pane is clicked; similar to what I have in the outer pane. The reason I'm confused here, is because the lazy load happens when the pane is clicked, but since this happens AFTER the databind, I don't know how to reference the content of the pane that invokes the ItemCommand. Not sure if that makes sense. Here is the inner accordion:
<ajaxToolkit:Accordion runat="server" ID="accReviewers" OnItemDataBound="accOuterAccordion_ItemDataBound" ContentCssClass="ReviewerContent" RequireOpenedPane="False" SelectedIndex="-1" OnItemCommand="accReviewers_ItemCommand">
<HeaderTemplate>
<div>
<asp:LinkButton Text='<%#Eval("Header") %>' CssClass="InReviewHeader" runat="server"
CommandName="LoadReviewers" CommandArgument='<%#Eval("MocRequestId") %>'/>
</div>
</HeaderTemplate>
<ContentTemplate>
<div>
<asp:ListView runat="server" ID="lvReviewers" ItemPlaceholderID="phReviewer" OnItemDataBound="lvReviewers_ItemDataBound">
<LayoutTemplate>
<div>
<asp:HyperLink runat="server" ID="lnkGotoRequest" Text="View this request"/>
</div>
<asp:PlaceHolder runat="server" ID="phReviewer"/>
<div style="margin-top: 5px;">
<asp:Button runat="server" ID="btnResubmit" Text="Resubmit" CssClass="ResubmitInitial"/>
</div>
</LayoutTemplate>
<ItemTemplate>
<div class="ReviewerItem">
<%#Eval("Assignee.Name") %><br />
<img src="" alt="Reviewer" runat="server" ID="imgReviewer" width="75" style="border: 1px solid gray; border-radius: 6px;"/><br />
<asp:Label runat="server" ID="lblStatus" Text='<%#Eval("ReviewStatus") %>' />
<asp:HyperLink runat="server" ID="lnkRejectComment" CssClass="InitialRejectComment">(details)</asp:HyperLink>
</div>
</ItemTemplate>
</asp:ListView>
</div>
</ContentTemplate>
</ajaxToolkit:Accordion>
</Content>
</ajaxToolkit:AccordionPane>
As you can see, the accordion accReviewers is generated via a DataSource. The listview contained in the LayoutTemplate will not have its datasource bound until the LinkButton has been clicked, which will fire the item command. Also worth noting that this entire accordion is wrapped in an UpdatePanel.
This is the code behind I was starting to work with, but it doesn't appear to get the correct instance of the listview and while the list is not empty, it will not display anything:
protected void accReviewers_ItemCommand(object sender, CommandEventArgs e)
{
var mocId = int.Parse(e.CommandArgument.ToString());
var list = (sender as AjaxControlToolkit.Accordion).FindControl("lvReviewers") as ListView; //APPARENTLY WRONG
var reviewers = MocApi.GetReviews(mocId);
list.DataSource = reviewers;
list.DataBind();
}
So to recap, when the LinkButton within the HeaderTemplate is clicked, I need to somehow gain reference to the correct instance of the ListView so that I can bind its datasource. As always, any help or insight is appreciated. This is similar to a previous question of mine but is specific to gaining this reference after databind which seems a bit more complicated. TIA
UPDATE:
I found that I can bind the item datasource if I can somehow capture its index. I'm exploring trying to set that as a command argument during the databinding of the inner accordion.

I managed to solve this with some minor shenannigans:
Here is the markup:
<ItemTemplate>
<div class="ReviewerItem">
<%#Eval("Assignee.Name") %><br />
<div style="display: inline-block; position: relative;">
<img src="" alt="Reviewer" runat="server" ID="imgReviewer" width="75" style="border: 1px solid lightgray; border-radius: 6px; overflow: hidden;"/><br />
<div runat="server" ID="divYes" Visible="False">
<img src="../Images/Yes.png" alt="Approved" class="ApprovalIcon" />
</div>
<div runat="server" ID="divNo" Visible="False">
<img src="../Images/No.png" alt="Rejected" class="ApprovalIcon" id="imgNo" />
</div>
</div>
<asp:Label runat="server" ID="lblStatus" Text='<%#Eval("ReviewStatus") %>' />
<asp:HyperLink runat="server" ID="lnkRejectComment" CssClass="InitialRejectComment">(details)</asp:HyperLink>
<asp:Panel runat="server" ID="pnlDemoApproval" Visible="False" CssClass="DemoButtons">
<asp:Button runat="server" ID="btnApprove" Text="Approve" CommandArgument='<%#Eval("Assignee.Guid") + "|" + Eval("Ticketid") %>' CommandName="ApproveReview"/>
<asp:Button runat="server" ID="btnDeny" Text="Deny" CommandArgument='<%#Eval("Assignee.Guid") + "|" + Eval("Ticketid") %>' CommandName="DenyReview"/>
</asp:Panel>
<ajaxToolkit:BalloonPopupExtender runat="server" ID="balloon" BalloonPopupControlID="pnlPopup"
TargetControlID="lnkRejectComment" Position="TopRight" BalloonStyle="Cloud" BalloonSize="Medium" DisplayOnMouseOver="True"/>
<asp:Panel runat="server" ID="pnlPopup">Rejection Reason</asp:Panel>
</div>
</ItemTemplate>
On databind, I catch the item so that I can grab the index and set it to the CommandName for later use:
AjaxControlToolkit.AccordionItemEventArgs e)
{
if (e.ItemType != AjaxControlToolkit.AccordionItemType.Content) return;
var index = e.ItemIndex;
var button = e.AccordionItem.Parent.FindControl("lnkbHeader") as LinkButton;
if (button != null) button.CommandName = index.ToString();
}
Now that control contains the index, i can use that to target the correct pane and bind its datasource:
protected void accReviewers_ItemCommand(object sender, CommandEventArgs e)
{
//This seems stupid to put here, but for some reason the item command bypasses the listview catch and passes it to the accordion
if (e.CommandName == "ApproveReview")
{
var assigneeGuid = new Guid(e.CommandArgument.ToString().Split('|')[0]);
var ticketId = int.Parse(e.CommandArgument.ToString().Split('|')[1]);
var ticket = new MocApproval(ticketId);
DoDemoApproval(ticketId, assigneeGuid, true);
var approvalIndex = (sender as AjaxControlToolkit.Accordion).SelectedIndex;
var lv =
(sender as AjaxControlToolkit.Accordion).Panes[approvalIndex].FindControl("lvReviewers") as ListView;
lv.DataSource = MocApi.GetReviews(ticket.MocRequest);
lv.DataBind();
return;
}
if (e.CommandName == "DenyReview")
{
var assigneeGuid = new Guid(e.CommandArgument.ToString().Split('|')[0]);
var ticketId = int.Parse(e.CommandArgument.ToString().Split('|')[1]);
var ticket = new MocApproval(ticketId);
DoDemoApproval(ticketId, assigneeGuid, false);
var approvalIndex = (sender as AjaxControlToolkit.Accordion).SelectedIndex;
var lv =
(sender as AjaxControlToolkit.Accordion).Panes[approvalIndex].FindControl("lvReviewers") as ListView;
lv.DataSource = MocApi.GetReviews(ticket.MocRequest);
lv.DataBind();
return;
}
...