How to set a value in a hidden field in accordance with the item selected in the drop-down list

Question

I have a dropdown that I create dynamically:

foreach(XmlNode item in doc.SelectNodes("//Monits/Monit")) {
    User newuser = new User();
    newuser.Id = item.SelectSingleNode("Id").InnerText;
    newuser.UserName = item.SelectSingleNode("UserName").InnerText;
    newuser.Email = item.SelectSingleNode("Email").InnerText;
    usersddl.Items.Add(newuser.UserName); //userddl is a tag on aspx              
}              

I want to know if there is a way to save the user id in a hidden field according to the changed item in my ddl. For example, I select the name Robbie from the drop-down list, and its identifier will be stored in the hidden value of the field value. I don’t have the code anymore because I don’t know where to start ... Help someone?

Answer 1

, . . , hanlder,

HiddenFieldID.Value=ddl.SelectedValue;

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<asp:DropDownList ID="ddl" runat="server" OnSelectedIndexChanged="ddl_SelectedIndexChanged"/>

protected void ddl_SelectedIndexChanged(sender object, EventArgs e)
{
     HiddenFieldID.Value=ddl.SelectedValue;
}