Develop Reference

ASP.NET - ImageButton within a Repeater refuses to raise a click event

No matter what combination I try, the button (ibtnDeleteDiaryEntry) simply will not raise an event although it does seem to do postback as it should. ViewState is turned on by default, read elsewhere that it is sometimes problematic. Also, I've used the Repeater's OnItemCommand property as required. Any kind of help is appreciated.
EDIT: It seems that the problem is somehow connected to the jQuery UI's Accordion Widget. The repeater is located within a div that is used to initialize the accordion. If I remove the div tags surrounding the repeater, the OnItemCommand event gets called. Very weird.
Markup:
<asp:Repeater ID="repAccordion" OnItemCommand="repAccordion_OnItemCommand" runat="server">
<ItemTemplate>
<h3> <%# "Date: " + Eval("date", "{0:d}") %>
<span class="deleteButtonContainer">
<asp:ImageButton ID="ibtnDeleteDiaryEntry" CommandArgument='<%# Eval("diary_entry_id") %>' CommandName="Delete" AlternateText="ibtnDeleteDiaryEntry" ImageUrl="images/remove_item.png" runat="server" />
</span>
</h3>
<div>
<table>
<tr>
<td>
<asp:Label ID="lblText" runat="server" ForeColor="#AA0114" Text="Text:"></asp:Label>
</td>
</tr>
<tr>
<td>
<%# Eval("text") %>
</td>
</tr>
</table>
</div>
</ItemTemplate>
</asp:Repeater>
Code-behind:
protected void Page_Load(object sender, EventArgs e)
{
_db = new PersonalOrganizerDBEntities();
_diary_entryService = new Diary_EntryService();
_userService = new UserService();
if (!IsPostBack)
{
LoadItems();
}
}
public void LoadItems()
{
long currentUserId = (long) Session["userId"];
User currentUser = _userService.GetById(currentUserId);
Diary_Entry[] diaryEntriesArray =
_diary_entryService.GetAll().Where(current => current.diary_id == currentUser.user_id).ToArray();
if (diaryEntriesArray.Length == 0)
{
noItems.Text = "You currently have no diary entries.";
noItems.Visible = true;
}
else
{
noItems.Visible = false;
}
repAccordion.DataSource = diaryEntriesArray;
repAccordion.DataBind();
}
protected void repAccordion_OnItemCommand(object sender, RepeaterCommandEventArgs e)
{
Response.Write("test");
}

If it doesn't work I would recommend removing OnItemCommand from repeater and adding OnClick event for ImageButton instead. In OnClick event in code behind you can cast 'sender' to ImageButton and read CommandArgument value to get diary_entry_id.

Showing buttons if list view is empty

I have a list view which retrieves the data from sql data source. I am trying to make two buttons(Yes and No) and a label outside the list view visible only if the list view is not empty. The process is: a person enter the information into text boxes and click the button retrieve, if the entered data exists in the database, the list view shows certain information.
I have the following code:
protected void btnExistingRetrive_Click(object sender, EventArgs e)
{
if (lstExisting.Items.Count>0 )
{
lblIsITYou.Visible = true;
btnYes.Visible = true;
btnNo.Visible = true;
}
}
By default buttons and the label are not visible.
The problem is when i click on retrieve button it shows me the list view with the information but buttons a the label are still not visible. They became visible only when i double click the retrieve button. Please tell me what is my mistake?
Thank you

Use the ListView EmptyDataTemplate
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
runat="server">
<LayoutTemplate>
<table runat="server" id="tblProducts">
<tr runat="server" id="itemPlaceholder" />
</table>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td>
<asp:Label ID="FirstNameLabel" runat="Server" Text='<%#Eval("FirstName") %>' />
</td>
<td>
<asp:Label ID="LastNameLabel" runat="Server" Text='<%#Eval("LastName") %>' />
</td>
</tr>
</ItemTemplate>
<EmptyDataTemplate>
<table class="emptyTable" cellpadding="5" cellspacing="5">
<tr>
<td>
<asp:Image ID="NoDataImage"
ImageUrl="~/Images/NoDataImage.jpg"
runat="server"/>
</td>
<td>
No records available.
</td>
</tr>
</table>
</EmptyDataTemplate>
</asp:ListView>

do you bind listview before checking the items count?

Do this on postback instead of in the event.
In your Page_Load do something like this:
protected void Page_Load(object sender, EventArgs e)
{
bool visible = (lstExisting.Items.Count > 0); // assuming it's never null
lblIsITYou.Visible = visible;
btnYes.Visible = visible;
btnNo.Visible = visible;
}
If the above creates complications then do as I said first with postback:
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
bool visible = (lstExisting.Items.Count > 0); // assuming it's never null
lblIsITYou.Visible = visible;
btnYes.Visible = visible;
btnNo.Visible = visible;
}
}

Defining the click event for a Login control integrated button

Gooday. I have a login control, with an integrated user textbox and login button. I did this little test to see how it works, and surprisingly, after doing this:
protected void LoginButton_Click(object sender, EventArgs e)
{
TextBox userTextBox = (TextBox)Login1.FindControl("UserName");
userTextBox.Text = "You pressed the button";
}
the userTextBox doesn't change to "You pressed the button". Why?
Thanks. Anna
EDIT: Sure, here is the markup (most of it is generated automatically by the system when adding the Login control); you will notice a button LoginButton integrated in the Login:
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:Panel ID="searchPanel" runat="server" DefaultButton="login1$LoginButton">
<asp:Login ID="Login1" runat="server"
FailureText="Logarea a esuat. Reincercati!" LoginButtonText="Logati-va!"
PasswordLabelText="Parola:"
PasswordRequiredErrorMessage="Trebuie sa introduceti parola."
RememberMeText="Tine-ma minte!" TitleText="Logare"
UserNameLabelText="Nume de utilizator:"
UserNameRequiredErrorMessage="Trebuie sa introduceti numele de utilizator.">
<LayoutTemplate>
<table border="0" cellpadding="1" cellspacing="0"
style="border-collapse:collapse;">
<tr>
<td>
<table border="0" cellpadding="0">
<tr>
<td align="center" colspan="2">
Logare</td>
</tr>
<tr>
<td align="right">
<asp:Label ID="UserNameLabel" runat="server" AssociatedControlID="UserName">Nume
de utilizator:</asp:Label>
</td>
.........
<tr>
<td align="right" colspan="2">
<asp:Button ID="LoginButton" runat="server" CommandName="Login"
Text="Logati-va!" ValidationGroup="Login1" />
</td>
</tr>
</table>
</td>
</tr>
</table>
</LayoutTemplate>
</asp:Login>
</asp:Panel>
</asp:Content>
The code-behind goes liek this:
namespace Cinemax
{
public partial class Login : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//userTextBox.Focus(); // this sets the focus on the username textbox when the page loads
this.Title = CinemaxConfiguration.SiteName + ": Login";
}
protected void LoginButton_Click(object sender, EventArgs e)
{
TextBox userTextBox = (TextBox)Login1.FindControl("UserName");
TextBox userPassword = (TextBox)Login1.FindControl("Password");
//Button loginBtn = (Button)Login1.FindControl("LoginButton");
userTextBox.Text = "You pressed me";
if (User1.ConnAttempt(userTextBox.Text, userPassword.Text) == 1)
{
Session["User"] = userTextBox.Text;
Response.Redirect("Catalog.aspx");
}
else
{
}
}
}
}

Is the TestBox an ASP server control, and is runat=Server?

I might be wrong, but do you ever actually bind it back to the control.
You are creating a new textbox that is initialised from your login control.
You then set the text of that textbox, but i dont think thta will bind it back to the control itself.

If you debug the application, does it show that the text gets set?
also, do you have something in the Page_Load method that sets the text box value? you should put things in a
if(!IsPostBack)
{
userTextBox.Text = ""
}
statement

check if your control is runat=server and you have binded the control to the event
this.LoginButton.Click += new System.EventHandler(this.LoginButton_Click);

In your login control check if you are setting some value of userTextBox in Page_Load or any other event, as it appears that its value is being set from somewhere else.

you have to bind it to the Form. . .

Change value of label and hide imagebutton in asp repeater

I've an asp repeater which has some fields inside an ItemTemplate. Each item in the repeater has an "add to cart" asp:ImageButton and an invisible asp:Label as well. The code looks like this:
<asp:Repeater ID="Repeater1" runat="server" OnItemCommand="addToCart">
<HeaderTemplate>
<table id="displayTable">
</HeaderTemplate>
<ItemTemplate>
<td>
<!-- fields like name, description etc in the repeater are present; i've omitted to show them here-->
<asp:Label ID="addedToCartLabel" runat="server" Visible="false"></asp:Label>
<asp:ImageButton ID="addToCartImg" runat="server" ImageUrl="hi.jpg" Width="75px" Height="50px" />
</td>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
When a particular ImageButton in the repeater is clicked, I'm trying to display "added to cart" as the text of its corresponding Label, and make the clicked ImageButton Visible=false. I've tried using the OnItemCommand function for the ASP:Repeater. The method is "addToCart":
<>
void addToCart(Object Sender, RepeaterCommandEventArgs e)
{
Cart cart = new Cart();
cart.instrument_id = //id of product from repeater based on user click
String userName = Membership.GetUser().ToString();
cart.user_name = userName;
cart.quantity = 1;
var thisLbl = (Label)e.Item.FindControl("addedToCartLabel");
var thisImg = (ImageButton)e.Item.FindControl("addToCartImg");
try
{
database.Carts.InsertOnSubmit(cart);
database.SubmitChanges();
thisImg.Visible = false;
thisLbl.Text = "Added to Cart!";
thisLbl.Visible = true;
}
catch (Exception ex)
{
thisImg.Visible = false;
thisLbl.Text = "Processing failed;please try again later";
thisLbl.Visible = true; ;
}
}
The aspx page is populated properly. However, when I click on any of the ImageButtons in the repeater, I get the following error:
Server Error in '/mysite' Application.
Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%# Page EnableEventValidation="true" %> in a page.
For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.
If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback
or callback data for validation.
Can someone help me with this?

May I suggest doing this with client-side javascript rather than a server-side call?
<asp:Label ID="addedToCartLabel" runat="server" Visible="false"></asp:Label>
<asp:ImageButton ID="addToCartImg" runat="server" ImageUrl="hi.jpg" Width="75px" Height="50px" />
becomes
<asp:Label ID="addedToCartLabel" runat="server" Visible="false"></asp:Label>
<asp:ImageButton ID="addToCartImg" runat="server" onclick="javascript:function() { this.this.style.display='none'; document.getElementById(this.parentNode.firstChild.id).style.display='block'; }" ImageUrl="hi.jpg" Width="75px" Height="50px" />

repeater databinding , with manipulation of certain data on every item binded

in a repeater, i want to do a function on every item bounded, example
<asp:Repeater runat="server" ID="rptArticleContent"
OnItemDataBound="rptArticleContent_ItemDataBound">
<ItemTemplate>
<tr>
<td width="365" valign="top" align="left" class="bodyContent" bgcolor="#FFFFFF">
<div>
<h2 class="h2">
<asp:Label runat="server" ID="dsds"> <%#Eval("Title") %></asp:Label>
</h2>
<div class="article-body">
<div class="Article-image">
<%#Eval("Image") %>
</div>
<%#Eval("Description") %>
</div>
<asp:Literal runat="server" ID="litArticleSource" Text='<%#Eval("Source") %>'>
</asp:Literal>
</td>
</tr>
</ItemTemplate>
</asp:Repeater>
in code behind i want to do some manipulation on the data inside the Literal
protected void rptArticleContent_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
Literal litArticleSource = rptArticleContent.FindControl
("litArticleSource") as Literal;
string ArticleSourcesR = litArticleSource.Text;
}
ArticleSourcesR still gives null, somes told me that when catching the controle with rptArticleContent.FindControl i should add something so it would be applied on every item bounded, what is that missing clue.?? what should be added?

You don't want to use rptArticleContent in the function, rather e.Item which will return the current repeater item instance.