Gets or sets a value that indicates whether the associated input control passes validation.
Assembly: System.Web (in System.Web.dll)
[<BrowsableAttribute(false)>] [<ThemeableAttribute(false)>] abstract IsValid : bool with get, set [<BrowsableAttribute(false)>] [<ThemeableAttribute(false)>] override IsValid : bool with get, set
Property ValueType: System.Boolean
true if the associated input control passes validation; otherwise, false. The default value is true.
Use the property to determine whether the associated input control passes validation.
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 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.
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 property for each validation control on the page is also set to true.
The following code example demonstrates how to use the property to determine whether the associated input control passes validation.
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.
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.