ValidationSummary.Render(HtmlTextWriter) Metodo
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Invia il contenuto del controllo server a un oggetto HtmlTextWriter specificato che scrive il contenuto di cui eseguire il rendering nel 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.
Esempio
Nell'esempio di codice seguente viene illustrato come eseguire l'override del Render metodo in un controllo server personalizzato in modo che il ValidationSummary controllo sia circondato da un Small tag.
Importante
L'esempio include una casella di testo che accetta l'input dell'utente e rappresenta quindi una potenziale minaccia alla sicurezza. Per impostazione predefinita, le pagine Web ASP.NET verificano che l'input dell'utente non includa script o elementi HTML. Per altre informazioni, vedere Cenni preliminari sugli attacchi tramite 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