ValidationSummary.Render(HtmlTextWriter) Metodo

Definizione

Invia il contenuto del controllo server a un oggetto HtmlTextWriter specificato che scrive il contenuto di cui eseguire il rendering nel client.Sends server control content to a provided HtmlTextWriter object, which writes the content to be rendered on the client.

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

Parametri

writer
HtmlTextWriter

Flusso di output che esegue il rendering del contenuto HTML nel client.The output stream that renders HTML content to the client.

Esempio

Nell'esempio di codice riportato di seguito viene illustrato come eseguire l'override del Render metodo in un controllo server personalizzato in modo che il ValidationSummary controllo sia racchiuso da un Small tag.The following code example demonstrates how to override the Render method in a custom server control so that the ValidationSummary control is surrounded by a Small tag.

Importante

L'esempio include una casella di testo che accetta l'input dell'utente e rappresenta quindi una potenziale minaccia alla sicurezza.This example has a text box that accepts user input, which is a potential security threat. Per impostazione predefinita, le pagine Web ASP.NET verificano che l'input dell'utente non includa script o elementi HTML.By default, ASP.NET Web pages validate that user input does not include script or HTML elements. Per altre informazioni, vedere Cenni preliminari sugli attacchi tramite script.For more information, see Script Exploits Overview.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" 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 ValidationSummary - Render - C# Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom ValidationSummary - Render - C# Example</h3>

      <table id="Table1" cellpadding="4" cellspacing="0">
        <tr>
          <td>
            <table id="Table2" cellpadding="4" cellspacing="0" style="background-color:#eeeeee">
              <tr>
                <td colspan="3"><b>Credit Card Information</b> </td>
              </tr>
              <tr>
                <td align="right">Card Type: </td>
                <td>
                  <asp:RadioButtonList id="RadioButtonList1" runat="server" RepeatLayout="Flow">
                      <asp:ListItem>MasterCard</asp:ListItem>
                      <asp:ListItem>Visa</asp:ListItem>
                  </asp:RadioButtonList>
                </td>
                <td align="center" rowspan="1">
                  <asp:RequiredFieldValidator 
                    id="RequiredFieldValidator1" 
                    runat="server" 
                    ErrorMessage="Card Type" 
                    Width="100%" 
                    Display="Static" 
                    ControlToValidate="RadioButtonList1">*
                  </asp:RequiredFieldValidator>
                </td>
              </tr>
              <tr>
                <td align="right">Card Number: </td>
                <td><asp:TextBox id="TextBox1" runat="server"></asp:TextBox></td>
                <td>
                  <asp:RequiredFieldValidator 
                    id="RequiredFieldValidator2" 
                    runat="server" 
                    ErrorMessage="Card Number" 
                    Width="100%" 
                    Display="Static" 
                    ControlToValidate="TextBox1">*
                  </asp:RequiredFieldValidator>
                </td>
              </tr>
              <tr>
                <td></td>
                <td><asp:Button id="Button1" runat="server" text="Validate"></asp:Button></td>
                <td></td>
              </tr>
            </table>
          </td>
        </tr>
        <tr>
          <td valign="top">
            <aspSample:CustomValidationSummaryRender
              id="ValidationSummary1" 
              runat="server" 
              DisplayMode="BulletList" 
              HeaderText="You must enter a value in the following fields:" />
          </td>
        </tr>
      </table>

        </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 ValidationSummary - Render - VB.NET Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom ValidationSummary - Render - VB.NET Example</h3>

            <table id="Table1" cellpadding="4" cellspacing="0">
                <tr>
                    <td>
                        <table id="Table2" cellpadding="4" cellspacing="0" style="background-color:#eeeeee">
                            <tr>
                                <td colspan="3"><b>Credit Card Information</b> </td>
                            </tr>
                            <tr>
                                <td align="right">Card Type: </td>
                                <td><asp:RadioButtonList id="RadioButtonList1" runat="server" RepeatLayout="Flow">
                                        <asp:ListItem>MasterCard</asp:ListItem>
                                        <asp:ListItem>Visa</asp:ListItem>
                                    </asp:RadioButtonList>
                                </td>
                                <td align="center" rowspan="1">
                                    <asp:RequiredFieldValidator id="RequiredFieldValidator1" 
                                        runat="server" ErrorMessage="Card Type" Width="100%" 
                                        Display="Static" ControlToValidate="RadioButtonList1">*</asp:RequiredFieldValidator>
                                </td>
                            </tr>
                            <tr>
                                <td align="right">Card Number: </td>
                                <td><asp:TextBox id="TextBox1" runat="server"></asp:TextBox></td>
                                <td>
                                    <asp:RequiredFieldValidator id="RequiredFieldValidator2" 
                                        runat="server" ErrorMessage="Card Number" Width="100%" 
                                        Display="Static" ControlToValidate="TextBox1">*</asp:RequiredFieldValidator>
                                </td>
                            </tr>
                            <tr>
                                <td></td>
                                <td><asp:Button id="Button1" runat="server" text="Validate"></asp:Button></td>
                                <td></td>
                            </tr>
                        </table>
                    </td>
                </tr>
                <tr>
                    <td valign="top">
                        <aspSample:CustomValidationSummaryRender
                         id="ValidationSummary1" runat="server" DisplayMode="BulletList" 
                         HeaderText="You must enter a value in the following fields:" />
                    </td>
                </tr>
            </table>

        </form>
    </body>
</html>
using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomValidationSummaryRender : System.Web.UI.WebControls.ValidationSummary
  {
    protected override void Render(System.Web.UI.HtmlTextWriter writer)
    {
      // Write out begining Small HTML tag.
      writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Small);

      // Call the base class's Render method.
      base.Render(writer);

      // Write out ending Small HTML tag.
      writer.RenderEndTag();
    }
  }
}
Imports System.Web
Imports System.Security.Permissions

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

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

            ' Write out begining Small HTML tag.
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Small)

            ' Call the base class's Render method.
            MyBase.Render(writer)

            ' Write out ending Small HTML tag.
            writer.RenderEndTag()
        End Sub
    End Class
End Namespace

Si applica a