Page.RegisterHiddenField Method (String, String)


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Note: 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.

Namespace:   System.Web.UI
Assembly:  System.Web (in System.Web.dll)

<ObsoleteAttribute("The recommended alternative is ClientScript.RegisterHiddenField(string hiddenFieldName, string hiddenFieldInitialValue).")>
Public Overridable Sub RegisterHiddenField (
	hiddenFieldName As String,
	hiddenFieldInitialValue As String


Type: System.String

The unique name of the hidden field to be rendered.

Type: System.String

The value to be emitted in the hidden form.

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

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.

System_CAPS_security Security Note

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.

     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)

.NET Framework
Available since 1.1
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