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CustomValidator.AddAttributesToRender(HtmlTextWriter) Méthode

  • Référence

Définition

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

Ajoute les propriétés du contrôle CustomValidator au flux de sortie pour le rendu sur le client.

protected:
 override void AddAttributesToRender(System::Web::UI::HtmlTextWriter ^ writer);
protected override void AddAttributesToRender (System.Web.UI.HtmlTextWriter writer);
override this.AddAttributesToRender : System.Web.UI.HtmlTextWriter -> unit
Protected Overrides Sub AddAttributesToRender (writer As HtmlTextWriter)

Paramètres

writer
HtmlTextWriter

HtmlTextWriter qui contient le flux de sortie pour la restitution sur le client.

Exemples

L’exemple de code suivant montre comment remplacer la AddAttributesToRender méthode dans un contrôle serveur personnalisé afin que le CustomValidator message d’erreur apparaisse toujours en gras.

Important

Cet exemple comprend une zone de texte qui accepte une entrée d'utilisateur, ce qui constitue une menace potentielle pour la sécurité. Par défaut, les pages web ASP.NET vérifient que l’entrée d’utilisateur n’inclut pas de script ou d’éléments HTML. Pour plus d’informations, consultez Vue d’ensemble des attaques de script.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet" Assembly="Samples.AspNet.CS" %>
<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>Custom CustomValidator - AddAttributesToRender - C# Example</title>
    <script runat="server">
    void CustomValidator1_ServerValidate(Object source, ServerValidateEventArgs args) 
    {
      try 
      {
        // Test whether the value entered into the text box is even.
        int i = int.Parse(args.Value);
        args.IsValid = ((i%2) == 0);
      }
      catch(Exception ex)
      {
        args.IsValid = false;
      }
    }
    </script>
  </head>
<body>
  <form id="Form1" method="post" runat="server">
    <h3>Custom CustomValidator - AddAttributesToRender - C# Example</h3>
    
    <asp:Label id="Label1" runat="server" 
    Text="Enter an even number:" AssociatedControlID="TextBox1"/><br />
    
    <asp:TextBox id="TextBox1" runat="server" /> 
    
    <aspSample:CustomCustomValidatorAddAttributesToRender 
      id="Customvalidator1" 
      runat="server" 
      ControlToValidate="TextBox1" 
      Display="Static" 
      ErrorMessage="Not an even number!" 
      OnServerValidate="CustomValidator1_ServerValidate" /><br /><br />
    
    <asp:Button id="Button1" runat="server" Text="Validate" />
    
  </form>
</body>
</html>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>Custom CustomValidator - AddAttributesToRender - VB.NET Example</title>
    <script runat="server">
      Sub CustomValidator1_ServerValidate(source As Object, args As ServerValidateEventArgs)
        args.IsValid = False
        Try
          ' Test whether the value entered into the text box is even or not.
          Dim i As Integer = Integer.Parse(args.Value)
          If (i Mod 2) = 0 Then
            args.IsValid = True
          End If
        Catch
        End Try
      End Sub
    </script>
  </head>
<body>
  <form id="Form1" method="post" runat="server">
    <h3>Custom CustomValidator - AddAttributesToRender - VB.NET Example</h3>
    <asp:Label id="Label1" runat="server" Text="Enter an even number:" AssociatedControlID="TextBox1" /><br />
    <asp:TextBox id="TextBox1" runat="server" /> 
    <aspSample:CustomCustomValidatorAddAttributesToRender id="Customvalidator1" runat="server" ControlToValidate="TextBox1" Display="Static" ErrorMessage="Not an even number!" OnServerValidate="CustomValidator1_ServerValidate" /><br /><br />
    <asp:Button id="Button1" runat="server" Text="Validate" />
  </form>
</body>
</html>

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomCustomValidatorAddAttributesToRender : System.Web.UI.WebControls.CustomValidator
    {
        protected override void AddAttributesToRender(System.Web.UI.HtmlTextWriter writer)
        {
        // Show the CompareValidator's error message as bold.
        writer.AddStyleAttribute(System.Web.UI.HtmlTextWriterStyle.FontWeight, "bold");
          
        // Call the Base's AddAttributesToRender method.
        base.AddAttributesToRender(writer);
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomCustomValidatorAddAttributesToRender
        Inherits System.Web.UI.WebControls.CustomValidator

        Protected Overrides Sub AddAttributesToRender(ByVal writer As System.Web.UI.HtmlTextWriter)

            ' Show the CompareValidator's error message as bold.
            writer.AddStyleAttribute(System.Web.UI.HtmlTextWriterStyle.FontWeight, "bold")

            ' Call the Base's AddAttributesToRender method.
            MyBase.AddAttributesToRender(writer)
        End Sub
    End Class
End Namespace

S’applique à