CustomValidator.AddAttributesToRender(HtmlTextWriter) Método

Definición

Espacio de nombres:
System.Web.UI.WebControls
Ensamblado:
System.Web.dll

Agrega las propiedades del CustomValidator control al flujo de salida para la representación en el cliente.

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)

Parámetros

writer
HtmlTextWriter

que HtmlTextWriter contiene el flujo de salida para la representación en el cliente.

Ejemplos

En el ejemplo de código siguiente se muestra cómo invalidar el AddAttributesToRender método en un control de servidor personalizado para que el CustomValidator mensaje de error siempre aparezca en negrita.

Importante

Este ejemplo tiene un cuadro de texto que acepta la entrada del usuario, que es una amenaza de seguridad potencial. De forma predeterminada, ASP.NET páginas web validan que la entrada del usuario no incluye elementos HTML ni de script. Para obtener más información, consulte Información general sobre vulnerabilidades de seguridad 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

Se aplica a