June 2002
Intermediate to advanced
816 pages
28h 12m
English
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Name
IsValid
Synopsis
Boolean = Page.IsValid
Returns a Boolean value, indicating whether any validation controls on the page were unable to successfully validate user input.
Parameters
-
Boolean A Boolean indicating whether the validation succeeded.
Example
The example uses the IsValid property to determine whether validation on the current page succeeded, and displays a message:
<%@ Page Language="vb" %>
<html>
<head>
<title></title>
<script runat="server">
Sub Page_Load( )
If IsPostBack Then
Page.Validate( )
If Page.IsValid Then
Message.Text = "Page is valid."
Else
Message.Text = "Page is not valid."
End If
End If
End Sub
</script>
</head>
<body>
<form runat="server">
Enter your name:
<asp:textbox id="name" runat="server"/>
<asp:requiredfieldvalidator
id="rfvName"
controltovalidate="name"
enableclientscript="false"
errormessage="Required!"
runat="server"/>
<br/>
<asp:button id="submit" Text="Submit" runat="server"/>
<br/>
<asp:label id="Message" runat="server"/>
</form>
</body>
</html>Notes
The IsValid property determines whether the overall validation
performed by a form’s validator controls has
succeeded. If the page has no validator controls, the
property’s value is always True.
Before checking the value of IsValid, you must either call the
Page.Validate method, as shown in the example, or have submitted the
page with a control (such as a Button, ImageButton, or LinkButton
control) whose CausesValidation property is set to
True. Otherwise, an exception will occur.
In the example, the ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.