ValidationSummary.OnPreRender(EventArgs) Metode
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Memunculkan kejadian PreRender.
protected:
override void OnPreRender(EventArgs ^ e);protected public:
override void OnPreRender(EventArgs ^ e);protected override void OnPreRender (EventArgs e);protected internal override void OnPreRender (EventArgs e);override this.OnPreRender : EventArgs -> unitProtected Overrides Sub OnPreRender (e As EventArgs)Protected Friend Overrides Sub OnPreRender (e As EventArgs)Parameter
Contoh
Contoh kode berikut menunjukkan cara mengambil alih OnPreRender metode sehingga selalu menampilkan pesan kesalahan sebagai tebal dalam kontrol server kustom ValidationSummary .
Penting
Contoh ini memiliki kotak teks yang menerima input pengguna, yang merupakan potensi ancaman keamanan. Secara default, ASP.NET halaman Web memvalidasi bahwa input pengguna tidak menyertakan elemen skrip atau HTML. Untuk informasi selengkapnya, lihat Gambaran Umum Eksploitasi Skrip.
<%@ 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 - AddAttributesToRender - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom ValidationSummary - AddAttributesToRender - 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:CustomValidationSummaryAddAttributesToRender
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 - AddAttributesToRender - VB.NET Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom ValidationSummary - AddAttributesToRender - 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>
<td valign="top">
<table id="Table3" cellpadding="4" cellspacing="0" >
<tr>
<td><aspSample:CustomValidationSummaryAddAttributesToRender
id="ValidationSummary1" runat="server" DisplayMode="BulletList"
HeaderText="You must enter a value in the following fields:" />
</td>
</tr>
</table>
</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 CustomValidationSummaryAddAttributesToRender : System.Web.UI.WebControls.ValidationSummary
{
protected override void AddAttributesToRender(System.Web.UI.HtmlTextWriter writer)
{
// Show the 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 CustomValidationSummaryAddAttributesToRender
Inherits System.Web.UI.WebControls.ValidationSummary
Protected Overrides Sub AddAttributesToRender(ByVal writer As System.Web.UI.HtmlTextWriter)
' Show the 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
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