c# - Catching "Maximum request length exceeded" -

i'm writing upload function, , have problems catching "system.web.httpexception: maximum request length exceeded" files larger specified max size in httpruntimein web.config (max size set 5120). i'm using simple <input> file.

the problem exception thrown before upload button's click-event, , exception happens before code run. how catch , handle exception?

edit: exception thrown instantly, i'm pretty sure it's not timeout issue due slow connections.

there no easy way catch such exception unfortunately. either override onerror method @ page level or application_error in global.asax, check if max request failure and, if so, transfer error page.

protected override void onerror(eventargs e) .....   private void application_error(object sender, eventargs e) {     if (globalhelper.ismaxrequestexceededexception(this.server.getlasterror()))     {         this.server.clearerror();         this.server.transfer("~/error/uploadtoolarge.aspx");     } } 

it's hack code below works me

const int timedoutexceptioncode = -2147467259; public static bool ismaxrequestexceededexception(exception e) {     // unhandled errors = caught @ global.ascx level     // http exception = caught @ page level      exception main;     var unhandled = e httpunhandledexception;      if (unhandled != null && unhandled.errorcode == timedoutexceptioncode)     {         main = unhandled.innerexception;     }     else     {         main = e;     }       var http = main httpexception;      if (http != null && http.errorcode == timedoutexceptioncode)     {         // hack: no real method of identifying if error max request exceeded          // treated timeout exception         if (http.stacktrace.contains("getentirerawcontent"))         {             // max request has been exceeded             return true;         }     }      return false; }