Hi everyone.
I have been building a vb.net application which works by sharing
data between a TCP clients and TCP server. The data being shared are small XML, CSV and PNG files. I have limited knowledge on TCP projects and thought it be a feasible idea to encode these files to Base64 send them
Base64 to the desired file information. This idea just doesn
TcpListener(IPAddress.Parse(IP), PORT)
SERVER.Start()
Threading.ThreadPool.QueueUserWorkItem(
TcpClient = SERVER.AcceptTcpClient
LIST_OF_CLIENTS.Add(CLIENT)
Threading.ThreadPool.QueueUserWorkItem(
NetworkStream = c.GetStream()
NEW_NETWORK_STREAM.Write(Encoding.UTF8.GetBytes(TEXT),
<pre lang=
"
vb"
>
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.IO
Public Class Form1
Const BUFFER_SIZE As Integer =
1024
*
20
Dim IP As
String
=
"
10.32.48.92"
Dim PORT As Integer =
5432
Dim CLIENT As New TcpClient(IP, PORT)
Private Sub Form1_Load(sender As
Object
, e As EventArgs) Handles MyBase.Load
'
(This connects to server)
CheckForIllegalCrossThreadCalls = False '
(
this
halts crossthreading errors cased by the way threads work, whic
is
apparently a big pain
in
the arse)
'
(Create a new thread to listen if connection is successfull... for the reciving of any new messages)
Threading.ThreadPool.QueueUserWorkItem(AddressOf RECIVE_MESAGES)
Me.AcceptButton = Button2 '
(This casses the enter key to triggre the button2.click
event
)
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub Button2_Click(sender As
Object
, e As EventArgs) Handles Button2.Click
'
sends filename, filelength, filebytes
Dim fullfilename As String = "C:\ToSomeFile.png"
Dim info As New FileInfo(fullfilename)
CLIENT.Connect(Net.IPAddress.Parse(IP), PORT) '
send the file to client IP address
'
writes a String and a Long with binarywriter (wrapping networkstream)
Dim bw As New BinaryWriter(CLIENT.GetStream)
bw.Write(info.Name)
bw.Write(info.Length)
'
using
filestream to read file, writes
this
directly to networkstream
Using fs As New FileStream(fullfilename, FileMode.Open, FileAccess.Read)
Dim buffer(BUFFER_SIZE) As
Byte
Dim reads As Integer = -1
Dim totalRead As Integer =
0
Do Until reads =
0
reads = fs.Read(buffer,
0
, buffer.Length)
CLIENT.GetStream.Write(buffer,
0
, reads)
totalRead += reads
End Using
bw.Close()
CLIENT.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub RECIVE_MESAGES(ByVal ar As IAsyncResult)
While True
Dim buffer(BUFFER_SIZE) As
Byte
Dim readstotal As Long =
0
'
using binaryreader (wrapped networkstream) to read a String and a Long
Dim br As New BinaryReader(CLIENT.GetStream)
Dim filename, filepath As String, filelen As Long
filename = br.ReadString
filelen = br.ReadInt64
If filename.ToUpper.Contains("PNG") Then
Dim di As New DirectoryInfo(Application.StartupPath & "\PNG")
If Not di.Exists Then
Directory.CreateDirectory(Application.StartupPath & "\PNG")
End If
filepath = Path.Combine(Application.StartupPath & "\PNG\", filename)
ElseIf filename.ToUpper.Contains("XML") Then
Dim di As New DirectoryInfo(Application.StartupPath & "XML")
If Not di.Exists Then
Directory.CreateDirectory(Application.StartupPath & "\XML")
End If
filepath = Path.Combine(Application.StartupPath & "\XML\", filename)
End If
Dim reads As Integer = -1
'
using
filestream to write read filebytes directly
from
networkstream
Using fs As New FileStream(filepath, FileMode.Create, FileAccess.Write)
Do Until readstotal = filelen
reads = CLIENT.GetStream.Read(buffer,
0
, buffer.Length)
fs.Write(buffer,
0
, reads)
readstotal += reads
End Using
End While
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
End Class
I
as
second attempt then returned to my initial idea and encoded the files to Base64 though
this
time before sending it via TCP I red the data
out
to a text-box copying the text-box results and checking on-line with diverse Base64 to Image sites
if
the Base64 code
from
the text-box delivered the same image which it did. I then proceeded with sending the data via TCP but am now met with a situation that says the Base64
is
incorrect the error says
"
The input is not a valid base-64 string as it contains a non-base 64 character..."
which after some more Googeling has lead me to believe the encoding of the
string
sent by the TCP corrupted the Base64 format apparently changing it to encoding.UTF8 would fix it however to no avail.
The following code show
this
attempt.
SERVER CODE:
Imports
System.Net
Imports
System.Net.Sockets
Imports
System.Text
Public
Class
Form1
Dim
SERVER
As
TcpListener
Dim
LIST_OF_CLIENTS
As
New
List(
Of
TcpClient)
Private
Sub
Button1_Click(sender
As
Object
, e
As
EventArgs)
Handles
Button1.Click
Dim
IP
As
String
=
"
10.43.71.241"
Dim
PORT
As
Integer
=
5432
SERVER =
New
TcpListener(IPAddress.Parse(IP), PORT)
SERVER.Start()
Threading.ThreadPool.QueueUserWorkItem(
AddressOf
NEW_CLIENT)
Catch
ex
As
Exception
MsgBox(ex.Message)
End
Try
End
Sub
Private
Sub
NEW_CLIENT()
Dim
CLIENT
As
TcpClient = SERVER.AcceptTcpClient
LIST_OF_CLIENTS.Add(CLIENT)
Threading.ThreadPool.QueueUserWorkItem(
AddressOf
NEW_CLIENT)
While
True
Dim
NETWORK_STREAM
As
NetworkStream = CLIENT.GetStream
Dim
BUFFER_TO_RECIVE(
1000000
)
As
Byte
NETWORK_STREAM.Read(BUFFER_TO_RECIVE,
0
, BUFFER_TO_RECIVE.Length)
Dim
TEXT
As
String
= Encoding.UTF8.GetString(BUFFER_TO_RECIVE)
For
Each
c
As
TcpClient
In
LIST_OF_CLIENTS
If
c
IsNot
CLIENT
Then
Dim
NEW_NETWORK_STREAM
As
NetworkStream = c.GetStream()
NEW_NETWORK_STREAM.Write(Encoding.UTF8.GetBytes(TEXT),
0
, TEXT.Length)
End
If
End
While
Catch
ex
As
Exception
If
LIST_OF_CLIENTS.Contains(CLIENT)
Then
LIST_OF_CLIENTS.Remove(CLIENT)
End
If
End
Try
End
Sub
CLIENT CODE:
<pre lang=
"
vb"
>
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.IO
Public Class Form1
Dim CLIENT As TcpClient
Private Sub Form1_Load(sender As
Object
, e As EventArgs) Handles MyBase.Load
'
(This connects to server)
Dim IP As String = "10.43.71.241"
Dim PORT As Integer = 5432
CLIENT = New TcpClient(IP, PORT)
CheckForIllegalCrossThreadCalls = False '
(
this
halts crossthreading errors cased by the way threads work, whic
is
apparently a big pain
in
the arse)
'
(Create a new thread to listen if connection is successfull... for the reciving of any new messages)
Threading.ThreadPool.QueueUserWorkItem(AddressOf RECIVE_MESAGES)
Me.AcceptButton = Button2 '
(This casses the enter key to triggre the button2.click
event
)
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub Button2_Click(sender As
Object
, e As EventArgs) Handles Button2.Click
Dim image As Image = image.FromFile(
"
C:\TOM\jane.png"
)
Dim format As System.Drawing.Imaging.ImageFormat = System.Drawing.Imaging.ImageFormat.Png
Using ms As New MemoryStream()
'
Convert Image to byte[]
image.Save(ms, format)
Dim imageBytes As Byte() = ms.ToArray()
'
Convert byte[] to Base64
String
Dim base64String As
String
= Convert.ToBase64String(imageBytes)
Dim NETWORK_STREAM As NetworkStream = CLIENT.GetStream
'
(Creates the nesesary stream)
NETWORK_STREAM.Write(Encoding.UTF8.GetBytes(base64String), 0, base64String.Length) '
(Writes the the stream just created
in
the above step)
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Using
End Sub
Private Sub RECIVE_MESAGES()
While True
Dim NETWORK_STREAM As NetworkStream = CLIENT.GetStream
Dim BUFFER_TO_RECIVE(
100000
) As
Byte
NETWORK_STREAM.Read(BUFFER_TO_RECIVE,
0
, BUFFER_TO_RECIVE.Length)
Dim TEXT As
String
= Encoding.UTF8.GetString(BUFFER_TO_RECIVE)
'
+++
Dim base64String As String = TEXT
'
Convert Base64
String
to byte[]
Dim imageBytes As
Byte
() = Convert.FromBase64String(base64String)
Dim ms As New MemoryStream(imageBytes,
0
, imageBytes.Length)
'
Convert byte[] to Image
ms.Write(imageBytes, 0, imageBytes.Length)
Dim image__1 As Image = Image.FromStream(ms, True)
PictureBox1.Image = image__1
Dim bm As New Bitmap(PictureBox1.Image)
bm.Save("c:\users\user\desktop\test.png", System.Drawing.Imaging.ImageFormat.Png)
'
(the following displays the text
in
ritch textbox)
TextBox3.Text = TEXT
End While
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
I seriously have made effort to
try
and figure
this
one
out
but just cant find the answer can anyone help me?
What I have tried:
See above section for examples i have tried
"This idea doesn't seem to work" doesn't tell us ANYTHING. Beyond that, TCP is merely a transoport mechanism and already uses "packets, so there's that...
Are you doing sopmething like this to encode images?
byte[] imageArray = System.IO.File.ReadAllBytes(
@"
path/imagefile.ext"
);
string
base64ImageRepresentation = Convert.ToBase64String(imageArray);
And this to decode images?
var
img = Image.FromStream(
new
MemoryStream(Convert.FromBase64String(base64String)));
I know, you're asking about VB, but this code is easily convertible...
Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad
spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or
edit the question
and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it.
Provide an answer or move on to the next question.
Let's work to help developers, not make them feel stupid.
