Get the text of a label in a listview

Question

I have a listview control which is populated with data from a database. I have used the label to display that data. Now I need to use the value of that label in some other place. I am trying to access the text value of the label control but it says

Object reference not set to an instance of an object.

But I do have value in the label.

<asp:ListView ID="msg_list" runat="server">
   <ItemTemplate>
    <table>
      <tr class="myitem">
        <td>
            <asp:Label ID="reg_id_reply" runat="server" Text="helo" Visible="false"  />
             <asp:Label role="menuitem" ID="msg_lbl" runat="server" text='<%#Eval("msg")%>' /><i style=" color:Gray; " >  from   
             <asp:Label ID="tme" runat="server" Text='<%#Eval("name")%>' />
             <i> on </i>
             <asp:Label ID="tmelbl" runat="server" Text='<%#Eval("tme")%>'/>
              <a id="msg-reply" class="btn button" data-toggle="modal" data-target="#msg-rply" style="cursor:pointer;" ><i class="glyphicon glyphicon-share-alt white"> </i></a>  </td>

              <hr style=" margin-top:1px; margin-bottom:1px; " />
      </tr>
     </table>
     <%--<hr style=" margin-top:1px; margin-bottom:1px; " />--%>
   </ItemTemplate>
  </asp:ListView>

This is how i tried to access the text of the label.Note that the code below is inside a button click event onClick of buttom.

Label mylbl = (Label)msg_list.FindControl("reg_id_reply");
string rid = mylbl.Text;

[What is a NullReferenceException and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Soner Gönül, Aug 06 '14 at 07:02
But i have text value in the label as you can see above `Text="helo"` — user35, Aug 06 '14 at 07:05
If you know the ID of the label, LabelID.Text will give the text value in label — SomeUser, Aug 06 '14 at 07:06
Yes it would if the label wasn't inside the ListView but i have that label inside the ListView. — user35, Aug 06 '14 at 07:11
Try this: put that entire C# code inside foreach (ListViewItem item in msg_list.Items){} — SomeUser, Aug 06 '14 at 07:32

score 0 · Answer 1 · edited May 23 '17 at 10:26

According to the description for Control.FindControl Method (String):

This method will find a control only if the control is directly contained by the specified container.

The direct container that your label is contained within is the ItemTemplate. Therefore you may need to build a recursive search for your label if you are starting with the listview. You could try the following code that is suggested from this MSDN page:

private Control FindControlRecursive(Control rootControl, string controlID)
{
    if (rootControl.ID == controlID) return rootControl;

    foreach (Control controlToSearch in rootControl.Controls)
    {
        Control controlToReturn = FindControlRecursive(controlToSearch, controlID);
        if (controlToReturn != null) return controlToReturn;
    }
    return null;
}

However also note that the listview may change the id values of components in the item template. If you know the item index you want then you can use the method suggested in this post:

var theLabel = this.ChatListView.Items[<item_index>].FindControl("reg_id_reply") as Label;

Get the text of a label in a listview

1 Answers1