.NET/html, element does not exist error when selecting dropdown.ClientID - asp.net

Question

On button click I want to get the value of a dropdown but for somereason when I go into the code it fails with error 'Exdd' does not exist in the current context. The ExTypeDD is in my listview as a dropdown and I'm just trying to get the value from it. The server side is generating this code and not my browser.
$('.Updt')
.click(function() {
var parent = $(this).parent().prev();
var TypeNode = parent.children("#<%=Exdd.ClientID %>").first();
<asp:ListView runat="server" id="ListView1" >
<LayoutTemplate>
<table id="tablesorter" style="border:solid 1px black;width:55%;">
<thead>
<tr>
<th>
Address
</th>
</tr>
</thead>
<tbody>
<tr id="itemPlaceholder" runat="server" />
</tbody>
<tfoot>
</tfoot>
</table>
</LayoutTemplate>
<ItemTemplate>
<tr>
<td>
<select id="Exdd"
class="Nbr1" style="width: 90px" >
<option value=""><%# Eval("Type")%></option>
<option value="0">Home</option></select>
</td>
<td>
<input type="button" id="btn_update" class="Updt" value="Update" />
</td>
</tr>
</ItemTemplate>
</asp:ListView>

Answer 1

You are in a ListView. You have as ExTypeDD as you have rows.
So you can not reference ExTypeDD successfully outside of the item template (there are more than one)
You may try ( after wrapping that up in a $(document).ready )
$('.Updt')
.click(function() {
var tr = $(this).closest('tr');
var TypeNode = tr.find("select.Nbr1").first();
//...
});

Answer 2

This is because you are trying to access an HTML element on the server side as a server side control. You could make your select element into a server side control by simply adding runat="server" to it like such:
<select id="ExTypeDD" runat="server" class="Nbr1" style="width:90px">
But after that you would still have the issue that this control, although accessible on the server side now, it does not have the id of ExTypeDD because it is dynamically created in the ItemTemplate of your ListView which generates a unique ID value for each newly created control . You can verify this by viewing source on the page rendered in the browser and checking the ID value on the select element.
To do what you're trying to do on the server side you would need to do something along the lines of this:
Add an onItemCreated event handler to your ListView:
<asp:ListView runat="server" id="ListView1" onItemCreated="ListView1ItemCreated">
Replace this:
<input type="button" id="btn_update" class="Updt" value="Update" />
With this:
<asp:button id="btn_update" text="Update" runat="server" />
Add the event handler to the code behind:
protected void ListView1ItemCreated(object sender, ListViewItemEventArgs e){
var myselect = (HtmlSelect)e.Item.FindControl("ExTypeDD");
var mybutton = (Button)e.Item.FindControl("btn_update");
mybutton.OnSubmit += (o,e) => {
// do something with myselect selected value
var selectedvalue = myselect.Value;
};
}
NOTE: the above code is not tested and probably won't compile, you will need to make necessary corrections, but it should give you the idea for a way to solve your problem. Hope it helps.