如何从后面的代码填充动态添加的html select控件？

Question

I've been programming in asp.net and c# for a week or so, please bear with me.

I'm trying to do a receipt generator in asp c# that looks kinda like this:

the blue button adds a new row to the table with this javascript function:

function nuevo(){
$("#tablaUsuarios").append("<tr>" +
    "<td><select name='listaConceptos' id='listaConceptos' runat='server'></select></td>" +
    "<td><input name='precio' id='precio' type='text' size='15' runat='server' readonly/></td>" +
    "<td><input type='button' value='Eliminar' onclick='eliminar(this)' class='btn btn-danger eliminar'></td>"+
    "</tr>")
}

However since I'm adding the controls via javascript on runtime, I have no access to them from the code behind like I would if they were DropDownList controls, adding runat="server" is also useless since at runtime I can't turn them into server controls, is there any way to access the control so I can populate, set data sources, etc. as if it were a DropDownList? Or any other way to dynamically generate and populate DDL?

I thought about having a hidden DropDownList populated with all the data I need from my database, and copying all its properties to the other select controls upon creation but I don't know if it would behave like a DDL with its DataValueFields and TextFields.

Answer 1

Check out the link below. Accessing client side dynamic controls within ASP.NET codebehind

You should be able to access the form elements by name on the server side like this:

var val = Request.Form["YOUR_CONTROLS_NAME"];

You will have to be responsible for naming the controls that you add with unique names though.

Answer 2

Client side and server side code are two different things. As far as I am aware there is no way to do what you are asking.

What you can do if you want to populate a drop down list from a database for example, is to load the data into a hidden field or control and then use javascript to populate the data.

Sounds rather complicated to me, maybe it would be easier to do everything server side and use update panels if you don't want an ugly postback.

Hard to tell what is best for you without fully seeing your project.