How to access JS variable in C#

Question

Let\'s say I have

500

(Context: asp.net aspx page) How do I allow a c# code access that value?

<

Answer 1

Use a hidden input box

Put your value in the input box with javascript

//call this method before you postback, maybe on form submit
function SetPostbackValues() {
  var hiddenControl = '<%= hiddenControl.ClientID %>';
  document.getElementById(hiddenControl).value = 500; 
  //or some other code to get your value
}

Access the value with the input box on the server side

protected void btnSubmit_Click(object sender, EventArgs e) {
   var hiddenValue = hiddenControl.Value;
}