我对这个套接字聊天有一点问题，如果我发送像“你好世界”这样的小消息它完全正常但是如果我尝试发送大约10,000个字符的巨大消息它只是崩溃，我一直在努力在过去3天没有运气的情况下解决这个问题，我该怎么办？
服务器来源：
Imports System.Text
Imports System.Net
Imports System.Net.Sockets
Enum Command
Login
'Log into the server
Logout
'Logout of the server
Message
'Send a text message to all the chat clients
List
'Get a list of users in the chat room from the server
Null
'No command
End Enum
Public Class Form1
'The ClientInfo structure holds the required information about every
'client connected to the server
Private Structure ClientInfo
Public socket As Socket
'Socket of the client
Public strName As String
'Name by which the user logged into the chat room
End Structure
'The collection of all clients logged into the room (an array of type ClientInfo)
Private clientList As ArrayList
'The main socket on which the server listens to the clients
Private serverSocket As Socket
Private byteData As Byte() = New Byte(1023) {}
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Try
clientList = New ArrayList()
'We are using TCP sockets
serverSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
'Assign the any IP of the machine and listen on port number 1000
Dim ipEndPoint As New IPEndPoint(IPAddress.Any, 2277)
'Bind and listen on the given address
serverSocket.Bind(ipEndPoint)
serverSocket.Listen(4)
'Accept the incoming clients
serverSocket.BeginAccept(New AsyncCallback(AddressOf OnAccept), Nothing)
Catch ex As Exception
MessageBox.Show(ex.Message, "SGSserverTCP", MessageBoxButtons.OK, MessageBoxIcon.[Error])
End Try
End Sub
Private Sub OnAccept(ar As IAsyncResult)
Try
Dim clientSocket As Socket = serverSocket.EndAccept(ar)
'Start listening for more clients
serverSocket.BeginAccept(New AsyncCallback(AddressOf OnAccept), Nothing)
'Once the client connects then start receiving the commands from her
clientSocket.BeginReceive(byteData, 0, byteData.Length, SocketFlags.None, New AsyncCallback(AddressOf OnReceive), clientSocket)
Catch ex As Exception
MessageBox.Show(ex.Message, "SGSserverTCP", MessageBoxButtons.OK, MessageBoxIcon.[Error])
End Try
End Sub
Private Sub OnReceive(ar As IAsyncResult)
Try
Dim clientSocket As Socket = DirectCast(ar.AsyncState, Socket)
clientSocket.EndReceive(ar)
'Transform the array of bytes received from the user into an
'intelligent form of object Data
Dim msgReceived As New Data(byteData)
'We will send this object in response the users request
Dim msgToSend As New Data()
Dim message As Byte()
'If the message is to login, logout, or simple text message
'then when send to others the type of the message remains the same
msgToSend.cmdCommand = msgReceived.cmdCommand
msgToSend.strName = msgReceived.strName
Select Case msgReceived.cmdCommand
Case Command.Login
'When a user logs in to the server then we add her to our
'list of clients
Dim clientInfo As New ClientInfo()
clientInfo.socket = clientSocket
clientInfo.strName = msgReceived.strName
clientList.Add(clientInfo)
'Set the text of the message that we will broadcast to all users
msgToSend.strMessage = "<<<" & msgReceived.strName & " has joined the room>>>"
Exit Select
Case Command.Logout
'When a user wants to log out of the server then we search for her
'in the list of clients and close the corresponding connection
Dim nIndex As Integer = 0
For Each client As ClientInfo In clientList
If client.socket Is clientSocket Then
clientList.RemoveAt(nIndex)
Exit For
End If
nIndex += 1
Next
clientSocket.Close()
msgToSend.strMessage = "<<<" & msgReceived.strName & " has left the room>>>"
Exit Select
Case Command.Message
'Set the text of the message that we will broadcast to all users
msgToSend.strMessage = msgReceived.strName & ": " & msgReceived.strMessage
Exit Select
Case Command.List
'Send the names of all users in the chat room to the new user
msgToSend.cmdCommand = Command.List
msgToSend.strName = Nothing
msgToSend.strMessage = Nothing
'Collect the names of the user in the chat room
For Each client As ClientInfo In clientList
'To keep things simple we use asterisk as the marker to separate the user names
msgToSend.strMessage += client.strName & "*"
Next
message = msgToSend.ToByte()
'Send the name of the users in the chat room
clientSocket.BeginSend(message, 0, message.Length, SocketFlags.None, New AsyncCallback(AddressOf OnSend), clientSocket)
Exit Select
End Select
If msgToSend.cmdCommand <> Command.List Then
'List messages are not broadcasted
message = msgToSend.ToByte()
For Each clientInfo As ClientInfo In clientList
If clientInfo.socket IsNot clientSocket OrElse msgToSend.cmdCommand <> Command.Login Then
'Send the message to all users
clientInfo.socket.BeginSend(message, 0, message.Length, SocketFlags.None, New AsyncCallback(AddressOf OnSend), clientInfo.socket)
End If
Next
Debug.Print(msgToSend.strMessage)
End If
'If the user is logging out then we need not listen from her
If msgReceived.cmdCommand <> Command.Logout Then
'Start listening to the message send by the user
clientSocket.BeginReceive(byteData, 0, byteData.Length, SocketFlags.None, New AsyncCallback(AddressOf OnReceive), clientSocket)
End If
Catch ex As Exception
MessageBox.Show(ex.Message, "SGSserverTCP", MessageBoxButtons.OK, MessageBoxIcon.[Error])
End Try
End Sub
Public Sub OnSend(ar As IAsyncResult)
Try
Dim client As Socket = DirectCast(ar.AsyncState, Socket)
client.EndSend(ar)
Catch ex As Exception
MessageBox.Show(ex.Message, "SGSserverTCP", MessageBoxButtons.OK, MessageBoxIcon.[Error])
End Try
End Sub
End Class
'The data structure by which the server and the client interact with
'each other
Class Data
Public strName As String
'Name by which the client logs into the room
Public strMessage As String
'Message text
Public cmdCommand As Command
'Command type (login, logout, send message, etcetera)
'Default constructor
Public Sub New()
cmdCommand = Command.Null
strMessage = Nothing
strName = Nothing
End Sub
'Converts the bytes into an object of type Data
Public Sub New(data__1 As Byte())
'The first four bytes are for the Command
cmdCommand = CType(BitConverter.ToInt32(data__1, 0), Command)
'The next four store the length of the name
Dim nameLen As Integer = BitConverter.ToInt32(data__1, 4)
'The next four store the length of the message
Dim msgLen As Integer = BitConverter.ToInt32(data__1, 8)
'This check makes sure that strName has been passed in the array of bytes
If nameLen > 0 Then
Me.strName = Encoding.UTF8.GetString(data__1, 12, nameLen)
Else
Me.strName = Nothing
End If
'This checks for a null message field
If msgLen > 0 Then
Me.strMessage = Encoding.UTF8.GetString(data__1, 12 + nameLen, msgLen)
Else
Me.strMessage = Nothing
End If
End Sub
'Converts the Data structure into an array of bytes
Public Function ToByte() As Byte()
Dim result As New List(Of Byte)()
'First four are for the Command
result.AddRange(BitConverter.GetBytes(CInt(cmdCommand)))
'Add the length of the name
If strName IsNot Nothing Then
result.AddRange(BitConverter.GetBytes(strName.Length))
Else
result.AddRange(BitConverter.GetBytes(0))
End If
'Length of the message
If strMessage IsNot Nothing Then
result.AddRange(BitConverter.GetBytes(strMessage.Length))
Else
result.AddRange(BitConverter.GetBytes(0))
End If
'Add the name
If strName IsNot Nothing Then
result.AddRange(Encoding.UTF8.GetBytes(strName))
End If
'And, lastly we add the message text to our array of bytes
If strMessage IsNot Nothing Then
result.AddRange(Encoding.UTF8.GetBytes(strMessage))
End If
Return result.ToArray()
End Function
End Class
客户来源：
Enum Command
Login '0 Log into the server
Logout '1 Logout of the server
Message '2 Send a text message to all the chat clients
List '3 Get a list of users in the chat room from the server
Null '4 No command
End Enum
Public Class frmMain
Public clientSocket As System.Net.Sockets.Socket
'The main client socket
Public strName As String
'Name by which the user logs into the room
Private byteData As Byte() = New Byte(1023) {}
Private Sub frmMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Call StartChat()
End Sub
Private Sub StartChat()
clientSocket = New System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp)
Dim ipAddress As System.Net.IPAddress = System.Net.IPAddress.Parse("127.0.0.1")
Dim ipEndPoint As New System.Net.IPEndPoint(ipAddress, 2277)
clientSocket.BeginConnect(ipEndPoint, New AsyncCallback(AddressOf OnLoginConnect), Nothing)
End Sub
Private Sub OnLoginConnect(ar As IAsyncResult)
clientSocket.EndConnect(ar)
'We are connected so we login into the server
Dim msgToSend As New Data()
msgToSend.cmdCommand = Command.Login
msgToSend.strName = txtUser.Text
msgToSend.strMessage = Nothing
Dim b As Byte() = msgToSend.ToByte()
'Send the message to the server
clientSocket.BeginSend(b, 0, b.Length, System.Net.Sockets.SocketFlags.None, New AsyncCallback(AddressOf OnLoginSend), Nothing)
End Sub
Private Sub OnLoginSend(ar As IAsyncResult)
clientSocket.EndSend(ar)
strName = txtUser.Text
Call LoggedIn()
End Sub
'***************
Private Sub LoggedIn()
'The user has logged into the system so we now request the server to send
'the names of all users who are in the chat room
Dim msgToSend As New Data()
msgToSend.cmdCommand = Command.List
msgToSend.strName = strName
msgToSend.strMessage = Nothing
byteData = msgToSend.ToByte()
clientSocket.BeginSend(byteData, 0, byteData.Length, System.Net.Sockets.SocketFlags.None, New AsyncCallback(AddressOf OnSend), Nothing)
byteData = New Byte(1023) {}
'Start listening to the data asynchronously
clientSocket.BeginReceive(byteData, 0, byteData.Length, System.Net.Sockets.SocketFlags.None, New AsyncCallback(AddressOf OnReceive), Nothing)
End Sub
'Broadcast the message typed by the user to everyone
Private Sub btnSend_Click(sender As Object, e As EventArgs) Handles btnSend.Click
'Fill the info for the message to be send
Dim msgToSend As New Data()
'.ToString("M/d/yyyy h:mm:ss tt")
msgToSend.strName = "[" & Date.Now.ToString("h:mm:ss tt") & "] <" & strName & ">"
msgToSend.strMessage = txtMessage.Text
msgToSend.cmdCommand = Command.Message
Dim byteData As Byte() = msgToSend.ToByte()
'Send it to the server
clientSocket.BeginSend(byteData, 0, byteData.Length, System.Net.Sockets.SocketFlags.None, New AsyncCallback(AddressOf OnSend), Nothing)
txtMessage.Text = Nothing
End Sub
Private Sub OnSend(ar As IAsyncResult)
clientSocket.EndSend(ar)
End Sub
Private Sub OnReceive(ar As IAsyncResult)
'clientSocket.EndReceive(ar)
Dim bytesReceived As Long = clientSocket.EndReceive(ar)
If (bytesReceived > 0) Then
Me.Invoke(New iThreadSafe(AddressOf iThreadSafeFinish), New Object() {byteData})
End If
byteData = New Byte(1023) {}
clientSocket.BeginReceive(byteData, 0, byteData.Length, System.Net.Sockets.SocketFlags.None, New AsyncCallback(AddressOf OnReceive), Nothing)
End Sub
Private Delegate Sub iThreadSafe(ByVal ibyteData As Byte())
Private Sub iThreadSafeFinish(ByVal ibyteData As Byte())
Dim msgReceived As New Data(ibyteData)
'Accordingly process the message received
Debug.Print(msgReceived.cmdCommand)
Select Case msgReceived.cmdCommand
Case 0 'login
lstChatters.Items.Add(msgReceived.strName)
Exit Select
Case 1 'log out
lstChatters.Items.Remove(msgReceived.strName)
Exit Select
Case 2 'msg
Exit Select
Case 3 'List
lstChatters.Items.AddRange(msgReceived.strMessage.Split("*"c))
lstChatters.Items.RemoveAt(lstChatters.Items.Count - 1)
txtChatBox.Text += "<<<" & strName & " has joined the room>>>" & vbCr & vbLf
Exit Select
End Select
If msgReceived.strMessage IsNot Nothing AndAlso msgReceived.cmdCommand <> Command.List Then
txtChatBox.Text += msgReceived.strMessage & vbCr & vbLf
End If
End Sub
Private Sub txtMessage_TextChanged(sender As Object, e As KeyEventArgs) Handles txtMessage.KeyDown
If e.KeyCode = Keys.Enter Then
btnSend_Click(sender, Nothing)
End If
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
strName = txtUser.Text
End Sub
End Class
'The data structure by which the server and the client interact with
'each other
Class Data
Public strName As String
'Name by which the client logs into the room
Public strMessage As String
'Message text
Public cmdCommand As Command
'Command type (login, logout, send message, etcetera)
'Default constructor
Public Sub New()
cmdCommand = Command.Null
strMessage = Nothing
strName = Nothing
End Sub
'Converts the bytes into an object of type Data
Public Sub New(data__1 As Byte())
'The first four bytes are for the Command
cmdCommand = CType(BitConverter.ToInt32(data__1, 0), Command)
'The next four store the length of the name
Dim nameLen As Integer = BitConverter.ToInt32(data__1, 4)
'The next four store the length of the message
Dim msgLen As Integer = BitConverter.ToInt32(data__1, 8)
'This check makes sure that strName has been passed in the array of bytes
If nameLen > 0 Then
strName = System.Text.Encoding.UTF8.GetString(data__1, 12, nameLen)
Else
strName = Nothing
End If
'This checks for a null message field
If msgLen > 0 Then
strMessage = System.Text.Encoding.UTF8.GetString(data__1, 12 + nameLen, msgLen)
Else
strMessage = Nothing
End If
End Sub
'Converts the Data structure into an array of bytes
Public Function ToByte() As Byte()
Dim result As New List(Of Byte)()
'First four are for the Command
result.AddRange(BitConverter.GetBytes(CInt(cmdCommand)))
'Add the length of the name
If strName IsNot Nothing Then
result.AddRange(BitConverter.GetBytes(strName.Length))
Else
result.AddRange(BitConverter.GetBytes(0))
End If
'Length of the message
If strMessage IsNot Nothing Then
result.AddRange(BitConverter.GetBytes(strMessage.Length))
Else
result.AddRange(BitConverter.GetBytes(0))
End If
'Add the name
If strName IsNot Nothing Then
result.AddRange(System.Text.Encoding.UTF8.GetBytes(strName))
End If
'And, lastly we add the message text to our array of bytes
If strMessage IsNot Nothing Then
result.AddRange(System.Text.Encoding.UTF8.GetBytes(strMessage))
End If
Return result.ToArray()
End Function
End Class
答案 0 :(得分：2)
您假设您一次会收到整条信息。 TCP不保证保留您编写的块。使用返回值bytesReceived来确定缓冲区中实际有多少字节。
您的代码必须能够处理一次一个字节接收所有未完成数据的可能性。