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HtmlTextArea.ServerChange Événement

  • Référence

Définition

Espace de noms:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Se produit lorsque le contenu du contrôle HtmlTextArea change entre des publications sur le serveur.

public:
 event EventHandler ^ ServerChange;
public event EventHandler ServerChange;
member this.ServerChange : EventHandler 
Public Custom Event ServerChange As EventHandler

Type d'événement

EventHandler

Exemples

L’exemple de code suivant montre comment spécifier et créer un gestionnaire d’événements personnalisé pour l’événement ServerChange . Un message s’affiche lorsque la valeur entrée dans le HtmlTextArea contrôle dépasse 10 caractères.

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

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

  void Server_Change(Object sender, EventArgs e)
  {

    // The ServerChange event is commonly used for data validation.
    // This method determines whether the comment entered into the
    // HtmlTextArea control is longer than 20 characters.
    if (TextArea1.Value.Length > 20)
      Span1.InnerHtml = "Your comment cannot exceed 20 characters.";
    else
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value;

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments: <br />

      <textarea rows="2" cols="20" id="TextArea1"
                onserverchange="Server_Change" 
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>

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

  Sub Server_Change(ByVal sender As Object, ByVal e As EventArgs)
         
    ' The ServerChange event is commonly used for data validation.
    ' This method determines whether the comment entered into the
    ' HtmlTextArea control is longer than 20 characters.
    If TextArea1.Value.Length > 20 Then
      Span1.InnerHtml = "Your comment cannot exceed 20 characters."
    Else
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value
    End If
      
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>

</head>
<body>

   <form id="form1" runat="server">

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments: <br />

      <textarea rows="2" cols="20" id="TextArea1"
                onserverchange="Server_Change" 
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>

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

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

  void Server_Change(Object sender, EventArgs e)
  {
    // The ServerChange event is commonly used for data validation.
    // This method determines whether the comment entered into the
    // HtmlTextArea control is longer than 20 characters.
    if (TextArea1.Value.Length > 20)
    {
      Span1.InnerHtml = "Your comment cannot exceed 20 characters.";
    }
    else
    {
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value;
    }

  }

  void Page_Load(Object sender, EventArgs e)
  {

    // Create an EventHandler delegate for the method you want to
    // handle the event, and then add it to the list of methods
    // called when the event is raised.
    TextArea1.ServerChange +=
      new System.EventHandler(this.Server_Change);

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments (20 or fewer characters): <br />

      <textarea rows="2" cols="20" id="TextArea1"
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>

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

  Sub Server_Change(ByVal sender As Object, ByVal e As EventArgs)
     
    ' The ServerChange event is commonly used for data validation.
    ' This method determines whether the comment entered into the
    ' HtmlTextArea control is longer than 20 characters.
    If TextArea1.Value.Length > 20 Then
         
      Span1.InnerHtml = "Your comment cannot exceed 20 characters."
         
    Else
         
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value
         
    End If
      
  End Sub

  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' Create an EventHandler delegate for the method you want to 
    ' handle the event, and then add it to the list of methods
    ' called when the event is raised.
    AddHandler TextArea1.ServerChange, AddressOf Server_Change

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>
</head>

<body>

   <form id="form1" runat="server">

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments (20 or fewer characters): <br />

      <textarea rows="2" cols="20" id="TextArea1"
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>

Remarques

L’événement ServerChange est déclenché lorsque le contenu du HtmlTextArea contrôle change entre les publications sur le serveur. Cet événement est couramment utilisé pour effectuer la validation des données sur la zone de texte.

Notes

Cet événement est déclenché uniquement lorsque l’utilisateur lance une publication sur le serveur, par exemple en cliquant sur un submit bouton. Cet événement n’entraîne pas de publication sur le serveur.

Notes

L’état d’affichage doit être activé pour que l’événement ServerChange fonctionne correctement.

Pour plus d’informations sur la façon de gérer les événements, consultez gestion et déclenchement d’événements.

S’applique à

Voir aussi