Using Arrays in Visual C#?

Question

I have a function that takes an array as a parameter. The function then fills the array up with information of unknown length. So how would I create an array to store a message of unknown length? Because I can't specify the size of the array since I don't know the size of the message it is going to store.

Would this be valid?

byte [] array;
function (array);

And then the size of the array will be determined by the size of the message it is filled in? If this isn't possible how would I do this?

I need the array to be the exact size of the message it is filled up with, so I can't just specify the array to be some random size big enough to fit the message.

Additional, from a comment:

public int ReceiveFrom( byte[] buffer, int offset, int size, 
       SocketFlags socketFlags, ref EndPoint remoteEP )

You can't. And that's why such interfaces don't exist in the library. — Henk Holterman
– Henk Holterman, Commented Dec 30, 2011 at 23:45
@DarrenYoung: one valid reason for downvoting is that the relevant info (again) has to be extracted form comments. The misunderstanding that caused the question is excusable, the (far) too short question itself is not. Also look at Fahrad's previosu question. — Henk Holterman
– Henk Holterman, Commented Dec 31, 2011 at 0:12
@HenkHolterman I specifically didn't specify the function prototype for a reason: The function that I mentioned is not the only function which is giving me a problem. In addition I have several other functions which is giving me the same problem. I cannot and will not waste time posting a variety of prototypes when the question is so generalized. — fdh
– fdh, Commented Dec 31, 2011 at 0:17
@Fahrad - one example would have cleared up a lot. As it finally did. — Henk Holterman
– Henk Holterman, Commented Dec 31, 2011 at 0:18
@HenkHolterman Your right, that was a fault on my part. I will be more specific next time. — fdh
– fdh, Commented Dec 31, 2011 at 0:27

xbrady · Accepted Answer · 2011-12-30 23:56:43Z

3

You can use a List and then once your message is filled call ToArray

Edit

Example:

List<byte> message = new List<byte>();
message.Add(/*your byte*/);
//More Adds
function(message.ToArray());

edited Dec 30, 2011 at 23:56

answered Dec 30, 2011 at 23:45

xbrady

1,70314 silver badges23 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

keyboardP Over a year ago

Not going to help. OP has no control over the method implementation or its signature, so passing anything other than an array is not possible.

xbrady Over a year ago

I see that now. That wasn't obvious before he commented on your answer.

Henk Holterman · Accepted Answer · 2011-12-31 00:04:42Z

2

About using

public int ReceiveFrom( byte[] buffer, int offset, int size, 
   SocketFlags socketFlags, ref EndPoint remoteEP )

You are supposed to use this in a loop. You are receiving parts of the total message (stream) at a time. Up to you to decide which part you need. Optionally shift the rest down and specify an offset in the next call.

byte[] buffer = new byte[1024];
ínt n;
do 
{
    n = ReceiveFrom(buffer, 0, buffer.Lenght, ...);

    if (n > 0)
        // process n bytes in buffer

} while (n > 0);

answered Dec 31, 2011 at 0:04

Henk Holterman

276k33 gold badges353 silver badges540 bronze badges

4 Comments

fdh Over a year ago

Thanks. The looping would only be required for TCP sockets though right? Or would this be for UDP sockets too?

Henk Holterman Over a year ago

I don't know UDP sockets but I'm quite certain it works the same way.

dtb Over a year ago

UDP is datagram-oriented, not stream-oriented. The buffer needs to be large enough to hold the entire datagram (up to 64 KiB). Otherwise the data gets truncated and the method throws a SocketException.

fdh Over a year ago

Thank You- I guess I won't need to loop then.

keyboardP · Accepted Answer · 2011-12-30 23:42:44Z

0

You could use a List instead. Although possible, you don't need to set a predetermined length and the List will expand as more objects are added.

answered Dec 30, 2011 at 23:42

keyboardP

69.5k13 gold badges162 silver badges209 bronze badges

16 Comments

fdh Over a year ago

It specifically has to be an array.

keyboardP Over a year ago

Does that mean you have no control over the function? (i.e. change it?)

M.Babcock Over a year ago

@Farhad - Can you post the function's signature?

Henk Holterman Over a year ago

@Fahrad: I thought so. You are just misunderstanding how socket I/O works.

M.Babcock Over a year ago

Please see the MSDN documentation regarding use of Socket.ReceiveFrom. It describes fairly well how it is intended to be called. msdn.microsoft.com/en-us/library/kbfwcz73.aspx

|

Eddie Paz · Accepted Answer · 2011-12-30 23:45:28Z

0

Do you need to do something with the array before passing it to the function that fills it up? If you don't, why don't you just return the array from the function instead of passing it one:

byte[] retArray = function();

where function is:

byte[] function()
{
}

You can then find out the length of the array by checking:

if( retArray != null )
{
  Console.WriteLine( retArray.Count );
}

answered Dec 30, 2011 at 23:45

Eddie Paz

2,25116 silver badges11 bronze badges

Comments

diggingforfire · Accepted Answer · 2011-12-30 23:46:42Z

0

It's hard to tell without knowing the exact details, but you could let the function create the array after it knows the length of the information.

Additionally, with Linq (using ToArray and ToList) you can cast from and to arrays and lists, but again, it's hard to tell without knowing the intentions.

answered Dec 30, 2011 at 23:46

diggingforfire

3,4091 gold badge27 silver badges34 bronze badges

Collectives™ on Stack Overflow

Using Arrays in Visual C#?

5 Answers 5

2 Comments

4 Comments

16 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

4 Comments

16 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related