BaseValidator.IsValid Property

 

Gets or sets a value that indicates whether the associated input control passes validation.

Namespace:   System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

[BrowsableAttribute(false)]
[ThemeableAttribute(false)]
public bool IsValid { get; set; }

Property Value

Type: System.Boolean

true if the associated input control passes validation; otherwise, false. The default value is true.

Use the IsValid property to determine whether the associated input control passes validation.

System_CAPS_cautionCaution

Because the default value of this property is true, it will return true if you query this property before validation is performed. For example, this might occur if you attempt to use this property in the Control.Load event of a page.

The IsValid property is evaluated only when the Validate method is called. You can call the Validate method for each validation control on the page individually, or call all of them at once by using the Page.Validate method. Button controls with their CausesValidation property set to true will also call the Page.Validate method.

System_CAPS_noteNote

It is possible to change the value of this property manually after validation has taken place. This allows you to override the validation result, if necessary.

The Page.IsValid property for the page is set to true only if the IsValid property for each validation control on the page is also set to true.

This property cannot be set by themes or style sheet themes. For more information, see ThemeableAttribute and ASP.NET Themes and Skins.

The following code example demonstrates how to use the IsValid property to determine whether the associated input control passes validation.

System_CAPS_security Security Note

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void Button_Click(Object sender, EventArgs e) 
  {
    if (NumberCompareValidator.IsValid && TextBoxRequiredValidator.IsValid)
    {
      MessageLabel.Text = "Page submitted successfully.";
    }
    else
    {
      MessageLabel.Text = "There is an error on the page.";
    }
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>Validator Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>Validator Example</h3>

      Enter a number from 1 to 10.
      <asp:textbox id="NumberTextBox" 
        runat="server"/>

      <asp:rangevalidator id="NumberCompareValidator" 
        controltovalidate="NumberTextBox"
        enableclientscript="False"  
        type="Integer"
        display="Dynamic" 
        errormessage="Please enter a value from 1 to 10."
        maximumvalue="10"
        minimumvalue="1"  
        text="*"
        runat="server"/>

      <asp:requiredfieldvalidator id="TextBoxRequiredValidator" 
        controltovalidate="NumberTextBox"
        enableclientscript="False"
        display="Dynamic" 
        errormessage="Please enter a value."
        text="*"
        runat="server"/>

      <br /><br />

      <asp:button id="SubmitButton"
        text="Submit"
        onclick="Button_Click"
        runat="server"/>

      <br /><br />

      <asp:label id="MessageLabel" 
        runat="server"/>

      <br /><br />

      <asp:validationsummary
        id="ErrorSummary"
        runat="server"/>

    </form>
  </body>
</html>

.NET Framework
Available since 1.1
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