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RangeValidator.EvaluateIsValid Méthode

  • Référence

Définition

Espace de noms:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Détermine si le contenu du contrôle d'entrée est valide.

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

Retours

Boolean

true si le contrôle est valide ; sinon, false.

Exemples

L’exemple de code suivant montre comment remplacer la EvaluateIsValid méthode dans un contrôle serveur personnalisé afin qu’elle valide toujours que la valeur existe et qu’elle se trouve dans les valeurs maximales et minimales spécifiées pour .RangeValidator

<%@ 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 RangeValidator - EvaluateIsValid - C# Example</title>
    <script runat="server">
      void ButtonClick(Object sender, EventArgs e)
      {
        if (Page.IsValid)
        {
          Label1.Text="Page is valid.";
        }
        else
        {
          Label1.Text="Page is not valid!!";
        }
      }
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom RangeValidator - EvaluateIsValid - C# Example</h3>

      Enter a number from 1 to 10:<br />
      <asp:TextBox id="TextBox1" Runat="server" />

      <aspSample:CustomRangeValidatorEvaluateIsValid 
        id="RangeValidator1" 
        runat="server" 
        ControlToValidate="TextBox1" 
        MinimumValue="1" 
        MaximumValue="10" 
        Type="Integer" 
        EnableClientScript="false" 
        Text="The value must be from 1 to 10!" />
        
      <br />
      <br />
      <asp:Button id="Button1" Text="Submit" OnClick="ButtonClick" runat="server" /><br />
      <br />

      <asp:Label id="Label1" runat="server" />
    </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 RangeValidator - EvaluateIsValid - VB.NET Example</title>
        <script runat="server">
            Sub ButtonClick(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 RangeValidator - EvaluateIsValid - VB.NET Example</h3>

            Enter a number from 1 to 10:<br />
            <asp:TextBox id="TextBox1" Runat="server" />
            
            <aspSample:CustomRangeValidatorEvaluateIsValid id="RangeValidator1" runat="server" 
             ControlToValidate="TextBox1" MinimumValue="1" MaximumValue="10" Type="Integer" 
             EnableClientScript="false" Text="The value must be from 1 to 10!" /><br />
             <br />
             
            <asp:Button id="Button1" Text="Submit" OnClick="ButtonClick" runat="server" /><br />
             <br />
             
            <asp:Label id="Label1" runat="server"/>
        </form>
    </body>
</html>

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

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomRangeValidatorEvaluateIsValid : System.Web.UI.WebControls.RangeValidator
  {
    protected override bool EvaluateIsValid()
    {
      // Get the value of the control to validate.
      string controlValue = GetControlValidationValue(ControlToValidate);

      // If no value was entered, show the validation error by returning false.
      if (controlValue.Trim().Length == 0) 
      {
        return false;
      }

      // Compare the ControlToValidate's value against the minimum and maximum values.
      return(Compare(controlValue, this.MinimumValue, System.Web.UI.WebControls.ValidationCompareOperator.GreaterThanEqual, this.Type) &&
        Compare(controlValue, this.MaximumValue, System.Web.UI.WebControls.ValidationCompareOperator.LessThanEqual, this.Type));
    }            
  }
}

Imports System.Web
Imports System.Security.Permissions

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

        Protected Overrides Function EvaluateIsValid() As Boolean

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

            ' If no value was entered, show the validation error by returning false.
            If controlValue.Trim().Length = 0 Then
                Return False
            End If

            ' Compare the ControlToValidate's value against the minimum and maximum values.
            Return Compare(controlValue, Me.MinimumValue, System.Web.UI.WebControls.ValidationCompareOperator.GreaterThanEqual, Me.Type) AndAlso _
                   Compare(controlValue, Me.MaximumValue, System.Web.UI.WebControls.ValidationCompareOperator.LessThanEqual, Me.Type)
        End Function
    End Class
End Namespace

S’applique à