ASP.NET Repeater: Button in item template to redirect to another page

Question

I have a repeater and each item contains a button which should redirect to another page and also pass a value in the query string.

I am not getting any errors, but when I click the button, the page just refreshes (so I am assuming a postback does occur) and does not redirect. I think that for some reason, it isn't recognizing the CommandName of the button.

Repeater code:

---

<asp:Repeater ID="MySponsoredChildrenList" runat="server" OnItemDataBound="MySponsoredChildrenList_ItemDataBound" OnItemCommand="MySponsoredChildrenList_ItemCommand">
    <HeaderTemplate>
    </HeaderTemplate>
    <ItemTemplate>
        <br />
        <div id="OuterDiv">
            <div id="InnerLeft">
                <asp:Image ID="ProfilePic" runat="server" ImageUrl='<%#"~/Resources/Children Images/" + String.Format("{0}", Eval("Primary_Image")) %>'
                    Width='300px' Style="max-height: 500px" /></div>
            <div id="InnerRight">
            <asp:HiddenField ID="ChildID" runat="server" Value='<%# DataBinder.Eval(Container.DataItem, "Child_ID") %>'/>   
                    <span style="font-size: 20px; font-weight:bold;"><%# DataBinder.Eval(Container.DataItem, "Name") %>
                    <%# DataBinder.Eval(Container.DataItem, "Surname") %></span>
                <br /><br /><br />

                What have you been up to?
                <br /><br />
                    <span style="font-style:italic">"<%# DataBinder.Eval(Container.DataItem, "MostRecentUpdate")%>"</span>    

                    <span style="font-weight:bold"> -<%# DataBinder.Eval(Container.DataItem, "Update_Date", "{0:dd/MM/yyyy}")%></span><br /><br /><br />Sponsored till:

                <%# DataBinder.Eval(Container.DataItem, "End_Date", "{0:dd/MM/yyyy}")%>
                <br /><br />

                <asp:Button ID="ChildProfileButton" runat="server" Text="View Profile"  CommandName="ViewProfile"  />
            </div>
        </div>
        <br />
    </ItemTemplate>
    <SeparatorTemplate>
        <div id="SeparatorDiv">
        </div>
    </SeparatorTemplate>
</asp:Repeater>

C# Code behind:

---

protected void MySponsoredChildrenList_ItemDataBound(object sender, RepeaterItemEventArgs e)
        {
            if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
            {
                // Stuff to databind
                Button myButton = (Button)e.Item.FindControl("ChildProfileButton");

                myButton.CommandName = "ViewProfile";                }
        }

        protected void MySponsoredChildrenList_ItemCommand(object source, RepeaterCommandEventArgs e)
        {
            if (e.CommandName == "ViewProfile")
            {
                int ChildIDQuery = Convert.ToInt32(e.Item.FindControl("ChildID"));
                Response.Redirect("~/ChildDescription.aspx?ID=" + ChildIDQuery);
            }

        }

I am new to using repeaters so it's probably just a rookie mistake. On a side note: is there a better way of obtaining the ChildID without using a hidden field?

EDIT: Using breakpoints; the ItemDatabound event handler is being hit, but the ItemCommand is not being entered at all

Answer 1

You need to set MySponsoredChildrenList_ItemDataBound as protected. Right now, you have just 'void' which by default is private, and is not accessible to the front aspx page.

Another way is to use the add event handler syntax from a function in your code behind, using the += operator.

Either way, the breakpoint will now be hit and our code should mwork.

EDIT: So the above solved the compilation error but the breakpoints are not being hit; I've ran some tests and am able to hit breakpoints like this:

Since I do not know how you are databinding, I just added this code to my code-behind:

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            MySponsoredChildrenList.DataSource = new List<object>() { null };
            MySponsoredChildrenList.DataBind();
        }
    }

Note: If you DataBind() and ItemDataBound() is called on every postback, it will wipe out the command argument, which is potentially what you are seeeing; so if you always see [object]_ItemDataBound() breakpoint hit, but never [object]_ItemCommand(), it is because you need to databind only on the initial page load, or after any major changes are made.

Note also the method MySponsoredChildrenList_ItemCommand doesn't work:

    protected void MySponsoredChildrenList_ItemCommand(object source, RepeaterCommandEventArgs e)
    {
        if (e.CommandName == "ViewProfile")
        {
            int ChildIDQuery = Convert.ToInt32(e.Item.FindControl("ChildID"));
            Response.Redirect("~/ChildDescription.aspx?ID=" + ChildIDQuery);
        }

    }

When you do FindControl, you need to cast to the correct control type, and also make sure to check for empty and null values before converting, or else you will possibly have errors:

    protected void MySponsoredChildrenList_ItemCommand(object source, RepeaterCommandEventArgs e)
    {
        if (e.CommandName == "ViewProfile")
        {
            int childId = 0;
            var hiddenField = e.Item.FindControl("ChildID") as HiddenField;
            if (null != hiddenField)
            {
                if (!string.IsNullOrEmpty(hiddenField.Value))
                {
                    childId = Convert.ToInt32(hiddenField.Value);
                }
            }

            if (childId > 0)
            {
                Response.Redirect("~/ChildDescription.aspx?ID=" + childId);
            }
        }

    }

Hope this helps - if not, please post additional code for the "full picture" of what is happening, so we can see where else you might have a problem.

Answer 2

I think on the repeater you need to add

OnItemDataBound="MySponsoredChildrenList_ItemDataBound"

Not 100% sure, but could be the same for the ItemCommand.

--

In regards to obtaining the ChildID. Add a CommandArgument to the button in the repeater, and set it in the same way, <% Eval("ChildID") %>. This can the be obtained using e.CommandArgument.

Answer 3

Try this.. Add an attribute to item row

row.Attributes["onclick"] = string.Format("window.location = '{0}';", ResolveClientUrl(string.Format("~/YourPage.aspx?userId={0}", e.Item.DataItem)) ); 

or You can do like this also

<ItemTemplate>      <tr onmouseover="window.document.title = '<%# Eval("userId", "Click to navigate onto user {0} details page.") %>'"          onclick='window.location = "<%# ResolveClientUrl( "~/YourPage.aspx?userId=" + Eval("userid") ) %>"'>           <td>                <%# Eval("UserId") %>           </td>      </tr> </ItemTemplate>