Επεξεργασία

Κοινή χρήση μέσω

BaseValidator.IsValid Property

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

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

public:
 property bool IsValid { bool get(); void set(bool value); };
[System.ComponentModel.Browsable(false)]
public bool IsValid { get; set; }
[System.ComponentModel.Browsable(false)]
[System.Web.UI.Themeable(false)]
public bool IsValid { get; set; }
[<System.ComponentModel.Browsable(false)>]
member this.IsValid : bool with get, set
[<System.ComponentModel.Browsable(false)>]
[<System.Web.UI.Themeable(false)>]
member this.IsValid : bool with get, set
Public Property IsValid As Boolean

Property Value

Boolean

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

Implements

IsValid
Attributes
BrowsableAttribute ThemeableAttribute

Examples

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

Important

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>

<%@ Page Language="VB" AutoEventWireup="False" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
 
  Sub Button_Click(ByVal sender As Object, ByVal e As EventArgs) Handles SubmitButton.Click
 
    If NumberCompareValidator.IsValid And TextBoxRequiredValidator.IsValid Then
    
      MessageLabel.Text = "Page submitted successfully."
    
    Else
    
      MessageLabel.Text = "There is an error on the page."
    
    End If
    
  End Sub
 
</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"
        runat="server"/>
 
      <br /><br />
       
      <asp:label id="MessageLabel" 
        runat="server"/>

      <br /><br />

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

Remarks

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

Caution

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.

Note

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.

Applies to

See also