ValidationSummary.Render(HtmlTextWriter) Método

  • Referência

Definição

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Envia o conteúdo do controle de servidor a um objeto HtmlTextWriter fornecido, que grava o conteúdo a ser renderizado no cliente.

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)

Parâmetros

writer
HtmlTextWriter

O fluxo de saída que renderiza o conteúdo HTML para o cliente.

Exemplos

O exemplo de código a seguir demonstra como substituir o Render método em um controle de servidor personalizado para que o ValidationSummary controle seja cercado por uma Small marca.

Importante

Este exemplo tem uma caixa de texto que aceita a entrada do usuário, que é uma possível ameaça à segurança. Por padrão, ASP.NET páginas da Web validam que a entrada do usuário não inclui elementos HTML ou script. Para obter mais informações, consulte Visão geral de explorações de script.

<%@ 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

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