ASP.NET How to read an HTML Form element?

Question

I have an ASP.NET web form where I have a hidden field, for example:

<form id="form1" runat="server" action="http://localhost/fa/Default.aspx">
        <div>
    <input id="requestData" type="hidden" name="requestData" value="" runat="server" />
    <asp:Button ID="btnPOST" Text="POST" runat="server" OnClick="do_POST" />
        </div>
    </form>

By the do_POST method, I have this:

    protected void do_POST(object sender, EventArgs e)
        {
//requestDataField is of the type protected global::System.Web.UI.HtmlControls.HtmlInputHidden requestData;

            requestDataField.Text = "FOO!";
        }

When I submit the form (by clicking the button), it goes to the server (handler) that I have:

string requestData = context.Request.Form["requestData"];

I get an empty string.

But if I assign a value like this:

<input id="requestData" type="hidden" name="requestData" value="FOO" runat="server" />

I get "FOO"

What am I missing?

Answer 1

, , , , ​​. , , .Text . , , . , , , , ( javascript, aspx). , .

Answer 2

do_POST , , , <input>. context.Request.Form["requestData"] , POST, , .

, onClick , . OnClientClick ( onClick). javascript :

<asp:Button ID="btnPOST" Text="POST" runat="server" OnClientClick="do_POST" /> 

<script>
  function do_POST() {
    document.getElementById("requestData").value = "FOO!";
  }
</script>

Answer 3

.

• requestDataField.Text = "FOO!"; requestData.Value = "FOO";

• . do_POST UseSubmitBehaviour False. .

, Javascript.

Answer 4

"" "" HtmlInputHidden:

requestDataField.Value = "FOO!";

instead

requestDataField.Text = "FOO!";