Question

Super newbie question here. I’m trying to teach myself Web Forms, so I’m experimenting with the runat="server" attribute. So here’s my code:

<p>
Number of items:
<input type="checkbox" name="custom_name_qty" value="25" runat="server" />25
<input type="checkbox" name="custom_name_qty" value="50" runat="server" />50
<input type="checkbox" name="custom_name_qty" value="75" runat="server" />75
<input type="checkbox" name="custom_name_qty" value="100" runat="server" />100
<input type="checkbox" name="custom_name_qty" value="Other" runat="server" />Other
</p>

And here’s what gets generated:

<p>
Number of items:
<input name="ctl01" type="checkbox" value="25" />25
<input name="ctl02" type="checkbox" value="50" />50
<input name="ctl03" type="checkbox" value="75" />75
<input name="ctl04" type="checkbox" value="100" />100
<input name="ctl05" type="checkbox" value="Other" />Other

So, it took my group of checkboxes that had the same name, and gave them separate names. Why is this? Even when I give them separate names (add an integer to the end of each one), they still get renamed.

What am I doing wrong here? How can I get the checkboxes to output the same name? How can I even get the checkboxes to keep the names that I give them? I’d rather work with a name I give than “ctl01”.

Answer 1

You are not doing anything wrong, that’s the default behaviour of asp.net. That is otherwise achieved with <asp:CheckListBox /> control: CheckListBox

  <asp:CheckBoxList id="checkboxlist1" 
       AutoPostBack="True"
       CellPadding="5"
       CellSpacing="5"
       RepeatColumns="2"
       RepeatDirection="Vertical"
       RepeatLayout="Flow"
       TextAlign="Right"
       OnSelectedIndexChanged="Check_Clicked"
       runat="server">

     <asp:ListItem>Item 1</asp:ListItem>
     <asp:ListItem>Item 2</asp:ListItem>
     <asp:ListItem>Item 3</asp:ListItem>
     <asp:ListItem>Item 4</asp:ListItem>
     <asp:ListItem>Item 5</asp:ListItem>
     <asp:ListItem>Item 6</asp:ListItem>

  </asp:CheckBoxList>

That shows how to add items manually. You can also populate the check list from database

  System.Data.DataTable dtOptions = GetValuesFromDataBase();
  checkboxlist1.DataSource = dtOptions;
  checkboxlist1.DataBind();

Update

In Asp.Net 4 and above, you are given more control on how control ID are generated (e.g. AutoID, Static, Predictable, Inherit)