How to set specific ID for server controls in an ASP.NET Web Form that is using a MasterPage?

Question

Is it possible to set a specific ID on an ASP.NET server control? Everytime I assign an ID and run the web form the ID changes.

For Example:

<asp:TextBox ID="txtName" runat="server"></asp:TextBox>

Gets translated into this:

<input id="ct100_ContentPlaceHolder1_txtName" type="text" />

I think this is do to me using master pages, but if so how can I be sure a control will have a certain ID(for javascript purposes). I placed the auto-generated id in my javascript and it is working, but I would prefer to have used the id's that I originally assigned them. Is this possible?

(This is for version:ASP.NET 3.5)

Answer 1

This is the way web controls ID's are in .NET prior to version 4.0. Version 4.0 introduces client IDs, which you can read about here.

You can use somthing like this in your JS:

var something = '<%= txtName.ClientID %>';

Answer 2

Starting with .NET 4 you have greater control about how the client-side IDs look like (see this post for details).

To force a specific client-side ID, you have to set the ClientIDMode to static. The following will render an <input> element with id="txtName":

<asp:TextBox ID="txtName" ClientIDMode="static" runat="server"></asp:TextBox>

Although if you do this, you have to ensure that you don't have two controls with identical client-side IDs. Check the article linked above for other options.

Answer 3

You can use the Control.ClientID property in your codebehind to get the actual id after it's been added to the control tree.

Super annoying choice made by the asp.net webforms people.