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RegularExpressionValidator.EvaluateIsValid Yöntem

Tanım

Giriş denetimindeki değerin geçerli olup olmadığını gösterir.

protected:
 override bool EvaluateIsValid();
protected override bool EvaluateIsValid ();
override this.EvaluateIsValid : unit -> bool
Protected Overrides Function EvaluateIsValid () As Boolean

Döndürülenler

true giriş denetimindeki değer geçerliyse; aksi takdirde , false.

Örnekler

Aşağıdaki kod örneği, özel bir sunucu denetiminde yönteminin EvaluateIsValid nasıl geçersiz kılındığını gösterir; böylece değeri her zaman bir içindeki RegularExpressionValidatoreşleşme için ifadeye karşı denetler.

Önemli

Bu örnekte, olası bir güvenlik tehdidi olan kullanıcı girişini kabul eden bir metin kutusu vardır. Varsayılan olarak, ASP.NET Web sayfaları kullanıcı girişinin betik veya HTML öğeleri içermediğini doğrular. Daha fazla bilgi için bkz . Betik Açıklarına Genel Bakış.

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomRegularExpressionValidatorEvaluateIsValid : System.Web.UI.WebControls.RegularExpressionValidator
  {
    protected override bool EvaluateIsValid()
    {
      // Get the control to validate's validation value
      string controlValue = GetControlValidationValue(this.ControlToValidate);
      
      // If the value is null or empty, then return true
      if (controlValue == null || controlValue.Trim().Length == 0) 
      {
        return true;
      }
      else
      {
        // Else try running the Regular Expression against the value 
        // and see if there is a match.
        try 
        {
          System.Text.RegularExpressions.Match regExpMatch = System.Text.RegularExpressions.Regex.Match(controlValue, this.ValidationExpression);
          return(regExpMatch.Success && regExpMatch.Index == 0 && regExpMatch.Length == controlValue.Length);
        }
        catch 
        {
          return true;
        }
      }
    }
  }
}
Imports System.Web
Imports System.Security.Permissions

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

        Protected Overrides Function EvaluateIsValid() As Boolean

            ' Get the control to validate's validation value
            Dim controlValue As String = GetControlValidationValue(Me.ControlToValidate)

            ' If the value is null or empty, then return true
            If controlValue Is Nothing OrElse controlValue.Trim().Length = 0 Then
                Return True
            Else
                ' Else try running the Regular Expression against the value 
                ' and see if there is a match.
                Try
                    Dim regExpMatch As System.Text.RegularExpressions.Match = System.Text.RegularExpressions.Regex.Match(controlValue, Me.ValidationExpression)
                    Return regExpMatch.Success AndAlso regExpMatch.Index = 0 AndAlso regExpMatch.Length = controlValue.Length
                Catch
                    Return True
                End Try
            End If
        End Function
    End Class
End Namespace

Aşağıdaki kod örneği, önceki örnekte tanımlanan denetimin CustomRegularExpressionValidatorEvaluateIsValid bir Web Forms sayfasında nasıl kullanılacağını gösterir.

<%@ 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 RegularExpressionValidator - EvaluateIsValid - C# Example</title>
    <script runat="server">
      void Button1_Click(Object sender, EventArgs e) 
      {
        if (Page.IsValid) 
        {
          Label1.Text = "Page is valid.";
        }
        else 
        {
          Label1.Text = "Page is invalid!";
        }
      }
    </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom RegularExpressionValidator - EvaluateIsValid - C# Example</h3>
       <table style="background-color:#eeeeee; padding:10">
          <tr valign="top">
             <td colspan="3">
                <asp:Label ID="Label1" 
                  Text="Enter a 5 digit zip code" 
                  runat="server"/>
             </td>
          </tr>
 
          <tr>
             <td colspan="3">
                <b>Personal Information</b>
             </td>
          </tr>
          <tr>
             <td align="right">
                Zip Code:
             </td>
             <td>
                <asp:TextBox id="TextBox1" runat="server"/>
             </td>
             <td>
                <aspSample:CustomRegularExpressionValidatorEvaluateIsValid
                  id="Regularexpressionvalidator1" 
                  runat="server"
                  ControlToValidate="TextBox1"
                  ValidationExpression="\d{5}"
                  ErrorMessage="Zip code must be 5 numeric digits"
                  Display="Static"
                  EnableClientScript="False" />
             </td>
          </tr>
          <tr>
             <td></td>
             <td>
                <asp:Button text="Button1" 
                  OnClick="Button1_Click" 
                  runat="server" ID="Button1"/>
             </td>
             <td></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 RegularExpressionValidator - EvaluateIsValid - VB.NET Example</title>
    <script runat="server">
      Sub Button1_Click(sender As Object, e As EventArgs)
          If Page.IsValid Then
              Label1.Text="Page is valid."
          Else
              Label1.Text="Page is not valid!"
          End If
      End Sub
    </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom RegularExpressionValidator - EvaluateIsValid - VB.NET Example</h3>
       <table style="background-color:#eeeeee; padding:10">
          <tr valign="top">
             <td colspan="3">
                <asp:Label ID="Label1" 
                  Text="Enter a 5 digit zip code" 
                  runat="server"/>
             </td>
          </tr>
 
          <tr>
             <td colspan="3">
                <b>Personal Information</b>
             </td>
          </tr>
          <tr>
             <td align="right">
                Zip Code:
             </td>
             <td>
                <asp:TextBox id="TextBox1" runat="server"/>
             </td>
             <td>
                <aspSample:CustomRegularExpressionValidatorEvaluateIsValid
                  id="Regularexpressionvalidator1" 
                  runat="server"
                  ControlToValidate="TextBox1"
                  ValidationExpression="\d{5}"
                  ErrorMessage="Zip code must be 5 numeric digits"
                  Display="Static"
                  EnableClientScript="False" />
             </td>
          </tr>
          <tr>
             <td></td>
             <td>
                <asp:Button text="Button1" 
                  OnClick="Button1_Click" 
                  runat="server" ID="Button1"/>
             </td>
             <td></td>
          </tr>
       </table>
        </form>
    </body>
</html>

Şunlara uygulanır

Ayrıca bkz.