Inserting NULLs into a message....

[PaulR]

Hi

I want to assemble messages for the Open Sound Control (OSC) protocol which requires padding out parts of the message with NULL values.

What would be the best way of doing that?

I assume I want to Dim Message() As Byte, but how to I append NULLs where I want them?

Cheers

Paul

 

[Erel]

Byte cannot be null. It is a number. You should probably put 0.

 

[PaulR]

Yes, that makes sense. What would be the syntax for appending values into a Byte? I am doing this...

Dim data() As Byte
data = "/foo".0.0.0.0.GetBytes("UTF8")

... but getting a syntax error (works without the zeros).

 

[Jost aus Soest]

GetBytes works only on strings and results in an byte array.

For example you could do something like this:

Dim data() As Byte
data = "/foo....".GetBytes("UTF8")  '<-- "." as placeholder
data(4) = 0
data(5) = 0
data(6) = 0
data(7) = 0

Or you use the chr-function, e. g.:

s = "/foo....".Replace(".", Chr(0))

or

s = "/foo" & Chr(0) & Chr(0) & Chr(0) & Chr(0)

 

[PaulR]

Thank you very much, the Replace method is perfect.

 

[Jost aus Soest]

You're welcome!

Jost

 

[PaulR]

Sorry, but how would I go around putting appending a Big Endian 32 bit twos compliment integer or a 32 bit floating point into a string?

 

[Jost aus Soest]

For such special cases you should use the ByteConverter library:
Basic4android - ByteConverter

 

[PaulR]

Thanks again! I've downloaded that and will have a play around with it. :sign0188:

 

[rbsoft]

@Jost

Nice picture. Is that inspired by the "Jäger von Soest", Simplicius Simplicissimus?

Rolf

 

[Jost aus Soest]

OT: Dat Jägerken von Soest

@rbsoft: Yes, you're right!

It's the symbol figure of Soest:
[Soest-Blog] Soester Weblog - Das Jägerken von Soest

I had the honor to represent the Jägerken last year!

 

[rbsoft]

Schickes Outfit!

Rolf

 

[PaulR]

Hi, sorry to derail the thread.

I have two messages, one is....


blah = "^^^1".Replace("^", Chr(0)).Replace("1",Chr(1))

blah = "~~~~".Replace("^", Chr(0)).Replace("~",Chr(255))

The first one when I.....

data = blah.GetBytes("UTF8")

... sends okay (a 1 value), but the second one sends -1010842689 instead of -1 (which is what 0xFFFFFFFF should be).

Any ideas as to what is happening, all I want to do is send FFFFFFFF....

:sign0013:

 

[PaulR]

Well it turns out that any value above 127 is sent in multiple bytes with UTF-8. 255 is an invalid value.

On a wing I tried GetBytes("ASCII") but it too doesn't send any value about 127, changing any value above that to 63.

I tried GetBytes(""), but it crashes the app.

So my revised question is how do I send byte values greater than 127 via UDP in Basic4Android?

edit: I have also been using the ByteConverter library StringToBytes function that requires stating what encoding will be used. The issue is that I don't want any encoding.

edit2: So my final question is... how do I send raw data via UDP? (I can send raw data, on a byte by byte basis, but want to store the information in a string, for conversion to ASCII values).