ReadBytes(buffer,0,buffer.Length)

[schimanski]

Hello together!

I tried to read a string from a server to bytes, but when I read out the buffer, most of the values are negativ. What can be the reason for that?

Dim buffer(100) As Byte
Dim InputStream1 as InputStream


If InputStream1.BytesAvailable > 0 Then
   bufferlength=InputStream1.ReadBytes(buffer,0,buffer.Length)
end if

Thanks or help....

 

[Erel]

The Bytes type values are between -128 to 127. These are signed bytes (there are no unsigned bytes in Java). However this should not bother you. You should use the keyword BytesToString to convert bytes arrays to string.

 

[schimanski]

Thanks, Erel!

Is it possible to transform it? I have to change the bytes into a binarystring and read out some informations out of parts of the binarycode. With the signed bytes, the binarystring is useless for me. I think, that BytesToString doesn't works for my application.

 

[Erel]

You can use the RandonAccessFile library to read unsigned bytes from buffer: Basic4android - RandomAccessFile

 

[schimanski]

Hello Erel, need something help!!!!

I have tried several codes to transform the buffer to an unsigned buffer of bytes, but it doen't work...:BangHead:
I think, that I use ReadUnsignedBytes i a wrong context.....

Dim buffer(100) As Byte
Dim InputStream1 as InputStream
Dim Transform As RandomAccessFile

Sub Read_from_server
..
  If InputStream1.BytesAvailable > 0 Then
     bufferlength=InputStream1.ReadBytes(buffer,0,buffer.Length)
  end if
..
end sub

Sub Transform_bytes
Transform.Initialize3(buffer,True)
..
  For i=0 To bufferlength               
    buffer(i)=Transform.ReadUnsignedByte(buffer(i),true)
  next
..
end sub

Thanks for help

 

[Erel]

You cannot store values larger than 127 in a byte variable.
What exactly are you trying to do? In most cases there is no need to convert the bytes like this.

 

[schimanski]

Hello Erel!

I only need the integer number apposite to the unsigned byte (0-255). The server from which I get the data sends a string of unsigned bytes. In basic4ppc I transform the byte with DecToBin in a binary code to get the informtions out of the binary string. The informations are always parses of different bytes. For example: To get an information, I have to transform the binary code of bit 4 to 8 from the first byte and bit 1 to 4 from the second byte to a decimalnumber with BinToDec...

I have read the standards: the informations are saved in the ascii-bytes 128-196..

 

[klaus]

A byte is a byte, the signed and unsigned problem appears only when you convert the byte into a number.

To get an unsigned number

Dim Signed, Unsigned As Int
 
Signed = buffer(i)
Unsigned = buffer(i) + 256

Best regards.

 

[schimanski]

That's all???:BangHead:

Thanks for that.....

 

[schimanski]

Hello Klaus!

I have tested it, but the solutions are not correct,every time.

I have now made it how Erel said:

dim buffer(100) as byte
dim buffer_int(100) as long

random1.Initialize3(buffer,False)

  For i=0 To buffer.length               
    buffer_int(i)=random1.ReadUnsignedByte(i)
  next

that works....

 

[Erel]

you can declare it as int (long consumes 4 more bytes).

 

[schimanski]

Yes, thanks for your efforts....

rgds