3 replies to this topic

[gordon128]

Hello fellow N+'s Code taken from: http://www.schuurmans.cc/tag/webserver I’ve use the code to do with this article and it does the job I’m looking for. How ever, I send a request to the server and all works OK. When I go to send another request a little later, it is as though the server has frozen. The only thing I can do is to re-boot the Netduino Plus. Below are the debug reports: ===========debug report=========== #### Exception System.NullReferenceException – CLR_E_NULL_REFERENCE (5) #### #### Message: #### Blinq.Netduino.Web.WebServer::InterpretRequest [IP: 0007] #### #### Blinq.Netduino.Web.WebServer::StartServer [IP: 0059] #### A first chance exception of type ‘System.NullReferenceException’ occurred in Blinq.Netduino.dll An unhandled exception of type ‘System.NullReferenceException’ occurred in Blinq.Netduino.dll ===========webserver.cs highlighted lines below=========== // Remove GET + Space string commandData = rawData.Substring(5, rawData.Length – 5); // Convert to string, will include HTTP headers. string rawData = new string(Encoding.UTF8.GetChars(bytes)); WebCommand command = InterpretRequest(rawData); Code taken from: http://www.schuurmans.cc/tag/webserver Please can anyone help on this matter. Regards Gordon

[Veetrik]

It could be that rawData length is less then 5, you can try replacing: string commandData = rawData.Substring(5, rawData.Length – 5); with: string commandData = (rawData.Lenght >= 5) rawData.Substring(5, rawData.Length – 5) ? ""; However, the real issue is why is the rawData length is less than 5?

[gordon128]

It could be that rawData length is less then 5, you can try replacing:
string commandData = rawData.Substring(5, rawData.Length – 5);
with:
string commandData = (rawData.Lenght >= 5) rawData.Substring(5, rawData.Length – 5) ? "";

However, the real issue is why is the rawData length is less than 5?

Veetrik,

Thanks for your reply. I tried what you suggested, but the assembler didn't like the code.
After some investigation I found my problem in the program.cs.
There was no trap for a bad command sent from the browser.

Thanks again Gordon

[Veetrik]

Veetrik,

Thanks for your reply. I tried what you suggested, but the assembler didn't like the code.
After some investigation I found my problem in the program.cs.
There was no trap for a bad command sent from the browser.

Thanks again Gordon

That's great Gordan. by the way the could I sent you should have been:

string commandData = (rawData.Lenght >= 5) ? rawData.Substring(5, rawData.Length – 5) : "";