Problem with Writing FileStream

Lost User

I answered this question yesterday and explained that you need to parse the input stream. You cannot assume that every name will be only 4 characters long. You already have the marker characters that separate your objects (&) and keyword value pairs (=), so you should be scanning your input stream for those characters to split the data into its constituent parts.

speaking as ...

Pete OHanlon

Software2007 wrote:

Any ideas what in the world is going on?

Sure - you have a randy image. As you've discovered, you can't rely on fixed lengths in your string here - instead, you need to find the index of the second =. You can do this with string.IndexOf to find it. The good news is that you know where the first = is based on your key here, so all you need to do is use IndexOf starting on the value 5 (the position after name= in your string).

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

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Luc Pattyn

Software2007 wrote:

the image shows the right size

where? how?

Software2007 wrote:

but can't be opened

when? by what program? has your app exited already? did you wait a full minute and try again? Please start taking the answers you get more seriously, and provide more detailed accurate information, so we all can help you more effectively. :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Lost User

Pete O'Hanlon wrote:

use IndexOf starting on the value 5

Not really a good suggestion based on the original question[^]. I get the impression he is trying to solve the problem by modifying the input data rather than getting to grips with the concept of parsing it.

speaking as ...

Pete OHanlon

Ah. I wasn't aware that he'd had an original question. Ho hum.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Lost User

Another one that's probably going to run and run ...

speaking as ...

Pete OHanlon

I suspect you're right.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Software2007

Luc: The image doesn't open up on disk, meaning I can't view the image. I have split the stream based on '&'. The bytes array apparently is full of them when it comes to image raw binary data. So, I decided to parse the string to the left of "image=". This is not where the problem is, the problem is after parsing, for the remaining image bytes, why can't I open the image correctly if the preceding string happens to be more than 16 chars long? The code above is only psuedo code, in reality this will be much longer string.

Trak4Net

Is it the exact same binary data for both preceding lengths? If not, maybe the stream exceeds the size of your byteArray buffer? The byte array should be initialized at the length of the stream without your preceeding string, not sure if you are doing that in live code but from your example it is a static value. Giving more information on your stream length and maybe even a sample of how you are generating the image would be helpful?

Luc Pattyn

If that's your best answer to my six questions, it stops here for me. Lacking the info, I'm not going to waste my time guessing what is going on. :(

Luc Pattyn [My Articles] Nil Volentibus Arduum

Software2007

Yes, it same exact image being generated, its sitting in my project folder. I tried dealing with static numbers to debug it easier. From iphone:

NSData *strData = ["name=tony&image=" datausingencoding:NSFTU8StringEncoding]
NSData *imageData = NSDATA(myImage)....raw binary representation of an image.....
[body appendData:strData];
[body appendData:imageData];
[request setHTTP body]

The WCF code in my original post works for any string <= 16 chars. If add an extra charcter and make it 17 chars "

"name=tony1&image="

, it stops working (of course I change the offset when I do that by one. Something is special aboutt he 16 char length here, may be it has to do with Encoding or something.

Software2007

This line was the problem, byte[] byteArray = new byte[10000]; I chose a randomly bigger number 20,000 and it works. But, it still doesn't make lot of sense to me. The bytesread for the image data alone is 5430. So, with extra 17 bytes string, I would think the 10000 would be still big enough? Is there a way to know how much to allocate instead of just guessing a large number? Stream.length seems to be problematic for me. Remember, this is a network stream that I don't know the size of containing image data.

Trak4Net

That is what I was talking about static values. If this is network stream you either need an end of message marker to make sure you read the whole message or read until nothing is left. You should be able to check what is available on the network stream and if multiple reads are required to get the entire message you may need to do some byte array manipulation (new byte() with current and new and use array.copy...) hope that is helpful.

Software2007

Thanks. I will look into it.