ClientScriptManager.RegisterHiddenField Method (System.Web.UI)

RegisterHiddenField Method

.NET Framework Class Library

ClientScriptManager..::.RegisterHiddenField Method

Registers a hidden value with the Page object.

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

Syntax

Visual Basic (Declaration)

Public Sub RegisterHiddenField ( _
    hiddenFieldName As String, _
    hiddenFieldInitialValue As String _
)

Visual Basic (Usage)

Dim instance As ClientScriptManager
Dim hiddenFieldName As String
Dim hiddenFieldInitialValue As String

instance.RegisterHiddenField(hiddenFieldName, _
    hiddenFieldInitialValue)

public void RegisterHiddenField(
    string hiddenFieldName,
    string hiddenFieldInitialValue
)

Visual C++

public:
void RegisterHiddenField(
    String^ hiddenFieldName, 
    String^ hiddenFieldInitialValue
)

JScript

public function RegisterHiddenField(
    hiddenFieldName : String, 
    hiddenFieldInitialValue : String
)

Parameters

hiddenFieldName: Type: System..::.String
The name of the hidden field to register.

hiddenFieldInitialValue: Type: System..::.String
The initial value of the field to register.

Exceptions

Exception	Condition
ArgumentNullException	hiddenFieldName is nullNothingnullptra null reference (Nothing in Visual Basic).

Remarks

The RegisterHiddenField method creates a hidden <input> element on the rendered HTML page.

Examples

The following code example demonstrates the use of the RegisterArrayDeclaration and RegisterHiddenField methods. The example registers an array and a hidden value and defines the OnClick event of an <input> button to calculate the sum of two values of the array and the hidden value.

Visual Basic

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

    ' Define the array name and values.
    Dim arrName As String = "MyArray"
    Dim arrValue As String = """1"", ""2"", ""text"""

    ' Define the hidden field name and initial value.
    Dim hiddenName As String = "MyHiddenField"
    Dim hiddenValue As String = "3"

    ' Define script name and type.
    Dim csname As String = "ConcatScript"
    Dim cstype As Type = Me.GetType()

    ' Get a ClientScriptManager reference from the Page class.
    Dim cs As ClientScriptManager = Page.ClientScript

    ' Register the array with the Page class.
    cs.RegisterArrayDeclaration(arrName, arrValue)

    ' Register the hidden field with the Page class.
    cs.RegisterHiddenField(hiddenName, hiddenValue)

    ' Check to see if the  script is already registered.
    If (Not cs.IsClientScriptBlockRegistered(cstype, csname)) Then
      Dim cstext As StringBuilder = New StringBuilder()
            cstext.Append("<script type=""text""/javascript> function DoClick() {")
      cstext.Append("Form1.Message.value='Sum = ' + ")
      cstext.Append("(parseInt(" + arrName + "[0])+")
      cstext.Append("parseInt(" + arrName + "[1])+")
      cstext.Append("parseInt(" + Form1.Name + "." + hiddenName + ".value));} </")
      cstext.Append("script>")
      cs.RegisterClientScriptBlock(cstype, csname, cstext.ToString(), False)
    End If

  End Sub

</script>

<html  >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form    id="Form1"
            runat="server">
     <input type="text"
            id="Message" />
     <input type="button" 
            onclick="DoClick()" 
            value="Run Script" />
     </form>
  </body>
</html>

<%@ Page Language="C#"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  public void Page_Load(Object sender, EventArgs e)
  {
    // Define the array name and values.
    String arrName = "MyArray";
    String arrValue = "\"1\", \"2\", \"text\"";

    // Define the hidden field name and initial value.
    String hiddenName = "MyHiddenField";
    String hiddenValue = "3";

    // Define script name and type.
    String csname = "ConcatScript";
    Type cstype = this.GetType();

    // Get a ClientScriptManager reference from the Page class.
    ClientScriptManager cs = Page.ClientScript;

    // Register the array with the Page class.
    cs.RegisterArrayDeclaration(arrName, arrValue);

    // Register the hidden field with the Page class.
    cs.RegisterHiddenField(hiddenName, hiddenValue);

    // Check to see if the  script is already registered.
    if (!cs.IsClientScriptBlockRegistered(cstype, csname))
    {
      StringBuilder cstext = new StringBuilder();
      cstext.Append("<script type=\"text\"/javascript> function DoClick() {");
      cstext.Append("Form1.Message.value='Sum = ' + ");
      cstext.Append("(parseInt(" + arrName + "[0])+");
      cstext.Append("parseInt(" + arrName + "[1])+");
      cstext.Append("parseInt(" + Form1.Name + "." + hiddenName + ".value));} </");
      cstext.Append("script>");
      cs.RegisterClientScriptBlock(cstype, csname, cstext.ToString(), false);
    }
  }
</script>
<html  >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form    id="Form1"
            runat="server">
     <input type="text"
            id="Message" />
     <input type="button" 
            onclick="DoClick()" 
            value="Run Script" />
     </form>
  </body>
</html>

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0

Reference

ClientScriptManager Class

ClientScriptManager Members

System.Web.UI Namespace

HiddenField