Assembly: System.Web (in system.web.dll)
The CustomError class provides a way to programmatically access and modify the error section of a configuration file. This type is part of a group that includes the CustomErrorCollection, CustomErrorsMode, and CustomErrorsSection.
When you define a custom error, ASP.NET assigns to it the standard error normally issued by the underlying service, such as IIS. For instance, if you define a custom error for the status code 404, ASP.NET will issue it anytime you refer to a non-existing .aspx page. The custom errors are only issued for those elements handled by ASP.NET. For instance, if you refer to a non-existing .htm page, IIS issues the standard 404 error.
This example demonstrates how to specify values declaratively for several attributes of the customErrors section, which can also be accessed as members of the CustomError class.
The following configuration file example shows how to specify values declaratively for the customErrors section.
<customErrors mode="RemoteOnly" defaultRedirect="customerror.htm"> <error statusCode="404" redirect="customerror404.htm"/> </customErrors>
The following code example demonstrates how to use the CustomError class.
// Get the Web application configuration. Configuration configuration = WebConfigurationManager.OpenWebConfiguration( "/aspnetTest"); // Get the section. CustomErrorsSection customErrors = (CustomErrorsSection)configuration.GetSection( "system.web/customErrors"); // Get the collection. CustomErrorCollection customErrorsCollection = customErrors.Errors;