ClientScriptManager.RegisterHiddenField(String, String) Metodo

Riferimento

Definizione

Spazio dei nomi:: System.Web.UI

Assembly:: System.Web.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Registra un valore nascosto con l'oggetto Page.

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

public void RegisterHiddenField (string hiddenFieldName, string hiddenFieldInitialValue);

member this.RegisterHiddenField : string * string -> unit

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

Parametri

hiddenFieldName: String

Nome del campo nascosto da registrare.

hiddenFieldInitialValue: String

Valore iniziale del campo da registrare.

Eccezioni

ArgumentNullException

hiddenFieldName è null.

Esempio

Nell'esempio di codice seguente viene illustrato l'uso dei RegisterArrayDeclaration metodi e RegisterHiddenField . Nell'esempio viene registrata una matrice e un valore nascosto e viene definito l'evento OnClick di un <input> pulsante per calcolare la somma di due valori della matrice e del valore nascosto.

<%@ 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>

<%@ 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>

Commenti

Il RegisterHiddenField metodo crea un elemento nascosto <input> nella pagina HTML di cui è stato eseguito il rendering.

Si applica a

Vedi anche

HiddenField

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