Byte - UDP

R

RosarioAR

Member
Licensed User
Longtime User
Hi to all
I have a question in reference to receive a bytes over UDP.
Im testing with an aplication in VB6 for to send the data.

I receive the data in B4A with the next code

B4X: 
Sub UDP_PacketArrived (Packet As UDPPacket)

   Dim msg As String
   Dim Buffer1() As Byte

   msg = BytesToString(Packet.data, Packet.Offset, Packet.Length, "UTF8")
   Buffer1=msg.GetBytes("UTF8")

I'm sendig data from VB6 with the next code

B4X: 
WinsockTX.SendData (Chr(1) & Chr(2) & Chr(255))

The problem is when i send a char > to 127, in Buffer1 i'm receiving 3 negative values that representing the 128 to 255 values (i'm expecting to receive 1 negative value). This negative values are the same from 128 to 255.

Values from 0 to 127 is OK
Buffer1 = [0=1, 1=2, 2=127]

Values from 128 to 255 Fail
Buffer1 = [0=1, 1=2, 2=-17, 3=-65, 4=-67]

How can i do to receive 1 negative value for next can be transform?

I read several treads respect to that, but im confused with the three negative values..

Thanks
 

Attachments

  • buffer status receiving chars 1 2 127.jpg
    30.2 KB · Views: 170
  • buffer status receiving chars 1 2 255.jpg
    28.8 KB · Views: 164
Sort by date Sort by votes
R

RosarioAR

Member
Licensed User
Longtime User
Hi Erel.
I'm converting the byte to string using the example in Basic4android - Network

B4X: 
Sub UDP_PacketArrived (Packet As UDPPacket)
    Dim msg As String
    msg = BytesToString(Packet.Data, Packet.Offset, Packet.Length, "UTF8")
    Msgbox("Message received: " & msg, "")
End Sub

Can i get directly the bytes from without convert to string?
I knew that Java use signed bytes, but i expected receive a negative value for then convert this.

Can you advise?
Thanks in advance.
 
Upvote 0
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…