Question

I’ve been looking for a reason why this doesn’t work, but I can’t find one. In my asp.net application I create a a bunch of hidden inputs in c# and then try to modify them in javascript before I call them back to the server.

My c# code:

    hidden3 = new HtmlInputHidden();
    hidden3.ID = "total";
    hidden3.Value = index.ToString();
    this.Controls.Add(hidden3);

my javascript code:

     mod = document.getElementById("total");
     mod.value = newVal;

I can call the value back fine but it doesn’t change. I have also added alerts for the original value and then the value after changing values and they both show up fine. However the code is never changed so when I pull the values

To get the value back I am using this;

    HtmlInputHidden hiddenControl = (HtmlInputHidden)FindControl("total");

Answer 1

These controls are dynamically created and they have to be created in each postback. However, these should be built before Page_Load preferably in Page_Init event handler. If these are created in Page_Load, the view state has already been processed and the control can’t be set from the posted value.