I am encountering an issue with retrieving hidden field values that were set during page load in the code behind. The problem arises when attempting to access these values in JavaScript, as they are returning as undefined or null. I am unable to retrieve the values that were initially set during page load in the code behind.
//code behind (C#) example
protected async void Page_Load(object sender, EventArgs e)
{
HiddenField_alt_edit.Value = "[{"unitid":"3072","unit_nameeng":"BOTTLE","purchcost":"2.000","salrate":"4.000","avgcost":"2.000","factor":"2"},{"unitid":"3073","unit_nameeng":"PKT","purchcost":"10.000","salrate":"20.000","avgcost":"10.000","factor":"10"}]";
ClientScriptManager script = Page.ClientScript;
script.RegisterClientScriptBlock(this.GetType(), "Alert", "<script type=text/javascript>addAlternativeRowWithData();</script>");
}
//aspx page content declaration
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:HiddenField ID="HiddenField_alt_edit" runat="server" Value="i am on."/>
</asp:Content>
// JavaScript function example
function addAlternativeRowWithData(mode)
{
alert("test");
var idvalue = $("#HiddenField_alt_edit").val();
alert(idvalue);
alert($nonconfli('#ContentPlaceHolder1_HiddenField_alt_edit').val());
var myHidden = document.getElementById('<%= HiddenField_alt_edit.ClientID %>').value;
alert(myHidden);
var json_string = $nonconfli('#ContentPlaceHolder1_HiddenField_alt_edit').val();
var arr_from_json = JSON.parse(json_string);
alert("test 2");
alert(arr_from_json);
}