Page.RegisterHiddenField(String, String) Method



This API is now obsolete.

Allows server controls to automatically register a hidden field on the form. The field will be sent to the Page object when the HtmlForm server control is rendered.

 virtual void RegisterHiddenField(System::String ^ hiddenFieldName, System::String ^ hiddenFieldInitialValue);
[System.Obsolete("The recommended alternative is ClientScript.RegisterHiddenField(string hiddenFieldName, string hiddenFieldInitialValue).")]
public virtual void RegisterHiddenField (string hiddenFieldName, string hiddenFieldInitialValue);
abstract member RegisterHiddenField : string * string -> unit
override this.RegisterHiddenField : string * string -> unit
Public Overridable Sub RegisterHiddenField (hiddenFieldName As String, hiddenFieldInitialValue As String)



The unique name of the hidden field to be rendered.


The value to be emitted in the hidden form.



The following code example uses the RegisterHiddenField method to help create ECMAScript code that is passed to the requesting browser. The name of the hidden field is set to myHiddenField and its value is set to "Welcome to Microsoft!" The RegisterStartupScript method calls the myHiddenField value when the user clicks a button on the page.


This example has a hidden field, which is a potential security threat. By default, you should validate the value of a hidden field as you would the value of a text box. ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

void Page_Load(Object sender, EventArgs e) 
   String scriptString = "<script language=\"JavaScript\"> function doClick() {";
   scriptString += "document.write('<h4>' + myForm.myHiddenField.value+ '</h4>');}<";
   scriptString += "/" + "script>";
   RegisterHiddenField("myHiddenField", "Welcome to Microsoft!"); 
   RegisterOnSubmitStatement("submit", "document.write('<h4>Submit button clicked.</h4>')"); 
   RegisterStartupScript("startup", scriptString);

     Dim scriptString As String = "<script language=""JavaScript""> function doClick() {"
scriptString += "document.write('<h4>' + myForm.myHiddenField.value+ '</h4>');}<"
scriptString += "/" + "script>"
RegisterHiddenField("myHiddenField", "Welcome to Microsoft!")

RegisterOnSubmitStatement("submit", "document.write('<h4>Submit button clicked.</h4>')")

RegisterStartupScript("startup", scriptString)


The RegisterHiddenField method has been deprecated. Use the RegisterHiddenField method in the ClientScriptManager class.

Applies to

See also