asp dropdownlist dynamic value from javascript issue

Question

I have a dropdownlist with 5 items. Value of last item is "other". By choosing "other" appears popup with input. The value of this input i set to this item by javascript. So value becoms inserted text. When i submitting the form, it doesn't work with this dynamic value, but other items of select works. Any ideas? Thanks very much!

Answer 1

Here is a quick example of using Request.Params collection to read dynamically added value.

Here is the client side code.

<!-- Server Control - Drop Down List -->
<asp:DropDownList ID="ddList" runat="server">
    <asp:ListItem Text="A" Value="A"></asp:ListItem>
    <asp:ListItem Text="B" Value="B"></asp:ListItem>
    <asp:ListItem Text="C" Value="C"></asp:ListItem>
</asp:DropDownList>

<!-- Control to fire JS event to add a new item to the Drop Down List above -->
<input type="button" value="Add Item D" id="AddItem" />

<!-- jQuery event to add a new option to the list on the click (no postback) -->
$('#AddItem').click(function ()
{
    $('#<%= ddList.ClientID %>').append('<option value="D">D</option>');
});

Here is the server side code to read the value.

var ddlListSelectedValue = Request.Params["ddList"];

Answer 2

Rather than set this value as droupdown list item value, you can use hiden field

<input type="hidden" id="hiddenField" runat="server" />

set value using JavaScript as below

document.getElementById ("hiddenField").value = "inputValue";

hiddenField value can access from code behind as below

string inputValue = hiddenField.Value;