My main issue is that I want to display an custom error page when an uploaded file exceeds allowed size (maxRequestLength in web.config).
When the big file is uploaded an HttpException is thrown before my upload action method in the controller is invoked. This is expected.
I have tried to catch the exception in a custom attribute and also to override OnException in the controller. Why isnt it possible to catch the exception in either the attribute or the OnException method?
Its possible though to catch the exception in Application_Error in global.asax but neither Response.Redirect nor Server.Transfer works for redirecting to the custom error page. Server.Transfer gives the "failed to process child request" error and response.redirect gives the "Http headers already sent" error.
Any ideas?
Thanks in advance!
Marcus
When running under IIS7 and upwards there is another parameter:
<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="10485760" />
</requestFiltering>
</security>
</system.webServer>
The default setting is slightly less than 30 MB.
For uploaded files with size between maxRequestLength
and maxAllowedContentLength
IIS7 will throw an HttpException
with HTTP code 500 and message text Maximum request length exceeded
. When this exception is thrown, IIS7 kills the connection immediately. So an HttpModule
that redirects on this error will only work if the HttpException
is handled and cleared (using Server.ClearError()
) in Application_Error()
in global.asax.cs.
For uploaded files with size bigger than maxAllowedContentLength
IIS7 will display a detailed error page with error code 404 and subStatusCode
13. The error page can be found in C:\inetpub\custerr\en-US\404-13.htm
For redirects on this error on IIS7 I recommend redirecting on httpErrors
instead.
To redirect to a different action set a smaller value for maxAllowedContentLength
than maxRequestLength
in web.config and also add the following to web.config:
<system.webServer>
<httpErrors errorMode="Custom" existingResponse="Replace">
<remove statusCode="404" subStatusCode="13" />
<error statusCode="404" subStatusCode="13" prefixLanguageFilePath=""
path="http://yoursite.com/Error/UploadTooLarge" responseMode="Redirect" />
</httpErrors>
</system.webServer>