Solved

send image via tcp/ip

Posted on 2008-10-30
3
2,214 Views
Last Modified: 2013-11-26
i am trying to send a picturebox image to a client computer using tcp.but im really struggling. i have converted the image to bytes before sending it. but i am having trouble converting the bytes back to image once it gets to the client. how do i determine the about of bytes to be read.
Server Side code'''''''''''''''''''''''''''''''''''''''
 Public Sub start()
        Listener.Start()
        Client = Listener.AcceptTcpClient
        Stream = Client.GetStream()
        '----
        w = New BinaryWriter(Stream)
        r = New BinaryReader(Stream)
        '----
        If r.ReadString() = "RequestConnect" Then
            w.Write("Connected")
            Do
                w.Write(imageToByteArray(Form1.PictureBox1.Image))
                w.Write("Connected")
            Loop Until r.ReadString() = "Disconnect"
            w.Write("Disconnected")
        End If
        Client.Close()
        Listener.Stop()
    End Sub
 
    Public Function imageToByteArray(ByVal imageIn As Image) As Byte()
        Dim ms As MemoryStream = New MemoryStream()
        imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.jpg)
        Return ms.ToArray()
    End Function
''---------------------------------------------------------------
 
CLIENT SIDE CODE''''''''''''''''''''''''''''''''''''''''''''''''''''
 Public Sub connect()
        Client.Connect(IP, port)
        Stream = Client.GetStream
        '----
        w = New BinaryWriter(Stream)
        r = New BinaryReader(Stream)
        '----
        
        w.Write("RequestConnect")
        If r.ReadString() = "Connected" Then
            Do
 ''HERES THE PROBLEM. how do i determine the amount of bytes to read
    Form1.PictureBox1.Image = byteArrayToImage(r.ReadBytes(126643))
                Application.DoEvents()
                w.Write("RequestConnect")
            Loop Until r.ReadString() = "Disconnected"
        End If
        Client.Close()
    End Sub
 
 Public Function byteArrayToImage(ByVal byteArrayIn() As Byte) As Image
        Dim ms As MemoryStream = New MemoryStream(byteArrayIn)
        Dim returnImage As Image = Image.FromStream(ms)
        Return returnImage
    End Function

Open in new window

0
Comment
Question by:carl5121
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 19

Accepted Solution

by:
drichards earned 250 total points
ID: 22846127
The best way to do it would be to send a header indicating the number of bytes to expect.  That way you can be sure to get them all.  Without that, the best you can do is to have a fixed size buffer (say 1024 bytes) and use the Read method.  You don't need the binary reader for this as it exists on the stream itself.

After doing a read, you transfer the bytes to a MemoryStream and then read again.  You read until no bytes are received for some period of time.  The problem is that you cannot predict the correct wait time as it might range from milliseconds to many seconds, or the data may not show up at all due to network conditions.  The most robust way to do it will be to send the image size in bytes ahead of the image data.  You'll need to make the header a fixed size so you know where the header ends and the image data starts.
0
 

Author Closing Comment

by:carl5121
ID: 31511682
thank you for your help. i've been looking for an answer for a week. i joined this website today and a good choice that was.
0
 
LVL 1

Expert Comment

by:agoud
ID: 25328194
This is how I do it with messages but it will have to be adapted to 'adding to the byte array'. I believe the keyphrase here is "While stream.DataAvailable". You will also have to use the stream (from Client.GetStream) directly. This is simply another way to do it.


While stream.DataAvailable
       i = stream.Read(bytes, 0, bytes.Length)
      Msg = Msg + System.Text.Encoding.ASCII.GetString(bytes, 0, i)
      Console.WriteLine("Received: {0}", Msg)
End While

Open in new window

0

Featured Post

Flexible connectivity for any environment

The KE6900 series can extend and deploy computers with high definition displays across multiple stations in a variety of applications that suit any environment. Expand computer use to stations across multiple rooms with dynamic access.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

The object model of .Net can be overwhelming at times – so overwhelming that quite trivial tasks often take hours of research. In this case, the task at hand was to populate the datagrid from SQL Server database in Visual Studio 2008 Windows applica…
This article shows how to deploy dynamic backgrounds to computers depending on the aspect ratio of display
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …

734 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question