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CustomValidator.AddAttributesToRender(HtmlTextWriter) Metode

  • Referensi

Definisi

Ruang nama:
System.Web.UI.WebControls
Rakitan:
System.Web.dll

Menambahkan properti CustomValidator kontrol ke aliran output untuk penyajian pada klien.

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)

Parameter

writer
HtmlTextWriter

HtmlTextWriter yang berisi aliran output untuk penyajian pada klien.

Contoh

Contoh kode berikut menunjukkan cara mengambil AddAttributesToRender alih metode dalam kontrol server kustom sehingga CustomValidator pesan kesalahan selalu muncul dalam huruf tebal.

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" 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

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