When a message (set of bytes) is sent over a network channel, of any type, there is no guarantee that the whole message will arrive as a single set of bytes.
The message might be split or merged together with other messages.
One way to overcome this issue is to initialize AsyncStreams in "prefix" mode. In this mode a 4 bytes header is added to each message with the message length. This allows AsyncStreams to internally build the messages correctly. However you can only use prefix mode if both sides of the connection adhere to this protocol. If for example you connect to a Bluetooth GPS then you cannot use prefix mode.
AsyncStreamsText can help you if:
1. The data sent is text and not binary data.
2. Each message ends with an end of line character (both Unix and Windows formats will work).
AsyncStreamsText works by handling the NewData event and looking for the end of line characters.
Using AsyncStreamsText is simple:
NewText event is raised each time that there is a complete message available.
Note that AsyncStreamsText.Write writes text and not bytes.
The charset field sets the encoding used to convert the bytes to string and vice versa.
The message might be split or merged together with other messages.
One way to overcome this issue is to initialize AsyncStreams in "prefix" mode. In this mode a 4 bytes header is added to each message with the message length. This allows AsyncStreams to internally build the messages correctly. However you can only use prefix mode if both sides of the connection adhere to this protocol. If for example you connect to a Bluetooth GPS then you cannot use prefix mode.
AsyncStreamsText can help you if:
1. The data sent is text and not binary data.
2. Each message ends with an end of line character (both Unix and Windows formats will work).
AsyncStreamsText works by handling the NewData event and looking for the end of line characters.
Using AsyncStreamsText is simple:
B4X:
Sub Process_Globals
Private ast As AsyncStreamsText
Private server As ServerSocket
End Sub
Sub Globals
End Sub
Sub Activity_Create(FirstTime As Boolean)
If FirstTime Then
server.Initialize(5555, "server")
Log(server.GetMyWifiIP)
server.Listen
End If
End Sub
Sub server_NewConnection (Successful As Boolean, NewSocket As Socket)
If Successful Then
If ast.IsInitialized Then ast.Close
ast.Initialize(Me, "ast", NewSocket.InputStream, NewSocket.OutputStream) 'initialize AsyncStreamsText with the socket streams.
Else
Log(LastException)
End If
server.Listen
End Sub
Sub ast_NewText(Text As String)
Log("Text: " & Text)
Log(Text.Length)
End Sub
Sub ast_Terminated
Log("Connection terminated")
End Sub
Sub Activity_Click
ast.Write("this is an example..." & Chr(10) & Chr(13))
End SubNewText event is raised each time that there is a complete message available.
Note that AsyncStreamsText.Write writes text and not bytes.
The charset field sets the encoding used to convert the bytes to string and vice versa.
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