.NET Framework Class Library
ClientScriptManagerRegisterHiddenField Method

Registers a hidden value with the Page object.

Namespace:   System.Web.UI
Assembly:  System.Web (in System.Web.dll)
Syntax
Public Sub RegisterHiddenField ( _
	hiddenFieldName As [%$TOPIC/bct5zt6z_en-us_VS_110_2_0_0_0_0%], _
	hiddenFieldInitialValue As [%$TOPIC/bct5zt6z_en-us_VS_110_2_0_0_0_1%] _
)
public void RegisterHiddenField(
	[%$TOPIC/bct5zt6z_en-us_VS_110_2_0_1_0_0%] hiddenFieldName,
	[%$TOPIC/bct5zt6z_en-us_VS_110_2_0_1_0_1%] hiddenFieldInitialValue
)
public:
void RegisterHiddenField(
	[%$TOPIC/bct5zt6z_en-us_VS_110_2_0_2_0_0%]^ hiddenFieldName, 
	[%$TOPIC/bct5zt6z_en-us_VS_110_2_0_2_0_1%]^ hiddenFieldInitialValue
)
member RegisterHiddenField : 
        hiddenFieldName:[%$TOPIC/bct5zt6z_en-us_VS_110_2_0_3_0_0%] * 
        hiddenFieldInitialValue:[%$TOPIC/bct5zt6z_en-us_VS_110_2_0_3_0_1%] -> unit
public function RegisterHiddenField(
	hiddenFieldName : [%$TOPIC/bct5zt6z_en-us_VS_110_2_0_4_0_0%], 
	hiddenFieldInitialValue : [%$TOPIC/bct5zt6z_en-us_VS_110_2_0_4_0_1%]
)

Parameters

hiddenFieldName
Type: SystemString

The name of the hidden field to register.

hiddenFieldInitialValue
Type: SystemString

The initial value of the field to register.

Exceptions
ExceptionCondition
ArgumentNullException

hiddenFieldName is .

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.

<%@ 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 xmlns="http://www.w3.org/1999/xhtml" >
  <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 xmlns="http://www.w3.org/1999/xhtml" >
  <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>
Version Information

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0