【发布时间】：2018-09-20 14:38:15
【问题描述】：
我正在构建一个带有简单套接字的 websocket 客户端 (vb.net)。 我这样做是为了在嵌入式项目（cc3220）上开始之前更好地理解它。
看来我通过握手就好了，在接收到一个文本帧后，数据停止接收。
websocket 服务器是 .net 核心 Azure 项目作为 echo。适用于具有多个连接的简单 websocket 客户端 chrome 扩展。
这是我的 VB.NET 应用程序的日志，也许有人能发现问题：
--- Sending via socket--
GET http://xxxxxxxx.azurewebsites.net/xxxxxxx HTTP/1.1
Host: xxxxxxxxxx.azurewebsites.net
Connection: Upgrade
Upgrade: WebSocket
Sec-WebSocket-Version: 13
Sec-WebSocket-Key: gnuE6HbBVfsHzYVNLdxxbQ==
--- New pack received---
total bytes:206
72,84,84,80,47,49,46,49,32,49,48,49,32,83,119,105,116,99,104,105,110,103,32,80,114,111,116,111,99,111,108,115,13,10,85,112,103,114,97,100,101,58,32,119,101,98,115,111,99,107,101,116,13,10,83,101,114,118,101,114,58,32,75,101,115,116,114,101,108,13,10,83,101,99,45,87,101,98,83,111,99,107,101,116,45,65,99,99,101,112,116,58,32,84,101,70,54,79,103,112,48,109,79,106,118,102,105,99,70,82,116,90,48,107,105,52,114,83,49,103,61,13,10,88,45,80,111,119,101,114,101,100,45,66,121,58,32,65,83,80,46,78,69,84,13,10,67,111,110,110,101,99,116,105,111,110,58,32,85,112,103,114,97,100,101,13,10,68,97,116,101,58,32,84,117,101,44,32,49,48,32,65,112,114,32,50,48,49,56,32,50,48,58,51,56,58,53,54,32,71,77,84,13,10,13,10,0,
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Server: Kestrel
Sec-WebSocket-Accept: TeF6Ogp0mOjvficFRtZ0ki4rS1g=
X-Powered-By: ASP.NET
Connection: Upgrade
Date: Tue, 10 Apr 2018 20:38:56 GMT
--- New pack receive---
total bytes:42
129,24,119,101,108,99,111,109,101,32,104,111,119,32,100,111,32,121,111,117,32,100,111,63,13,10,129,14,110,101,119,32,99,111,110,110,101,99,116,105,111,110,32,
welcome how do you do?
new connection
Length: 24 op_code: 1(string data)
-- sending data (string 123) via socket, here there is no respond, the server should echo this ----
Sending string: 123
Sending bytes: 129,3,49,50,51,
Sending string: 123
Sending bytes: 129,3,49,50,51,
--- even when sending data via another websocket client app, the data is not received here, but it does to the third websocket client app ---
Vb代码：
Public Class SocketObject
Public socket As Socket = Nothing
Public Const BUFFER_SIZE As Integer = 1024
Public buffer(BUFFER_SIZE) As Byte
End Class 'StateObject
Dim sock As New SocketObject()
Private Sub printbytes(ByVal bytes() As Byte, ByVal size As Int16)
Dim i As Integer = 0
Dim a As String = vbCrLf + "--- New pack receive--- " + vbCrLf + "total bytes:" + size.ToString() + vbCrLf
Dim b As String = ""
For i = 0 To size
a += bytes(i).ToString() + ","
b += Chr(bytes(i))
Next
Dim c As String = ""
If (bytes(0) >= &H0) And (bytes(0) <= &H7F) Then
c = "(0x00 to 0x7F) --> Data... --> 0xFF "
Else
c = "(0x80 to 0xFF) --> Length --> Data..."
c += " Length: " + bytes(1).ToString()
Dim op_code As Byte = bytes(0) And &HF
c += " op_code: " + op_code.ToString()
Select Case op_code
Case 9
c += "(ping) response - Pong"
Dim ascii As Encoding = Encoding.UTF8
Dim request As String = " Pong"
Dim bytesSent As [Byte]() = ascii.GetBytes(request)
bytesSent(0) = &H8A
bytesSent(1) = 4
' Send request to the server.
sock.socket.Send(bytesSent, bytesSent.Length, 0)
Case 10
c += "(pong)"
Case 1
c += "(string data)"
Case 2
c += "(binary data)"
Case 8
c += "(connection close) - response and close"
Dim ascii As Encoding = Encoding.UTF8
Dim request As String = " "
Dim bytesSent As [Byte]() = ascii.GetBytes(request)
bytesSent(0) = &H8
' Send request to the server.
sock.socket.Send(bytesSent, bytesSent.Length, 0)
Case Else
c += "(unknown!!)"
End Select
End If
Me.Dispatcher.Invoke(Windows.Threading.DispatcherPriority.Background, New Delegate_LableAddText(AddressOf LableAddText), a + vbCrLf + b + vbCrLf + c + vbCrLf + vbCrLf)
End Sub
Public Sub Read_Callback(ar As IAsyncResult)
Dim so As SocketObject = CType(ar.AsyncState, SocketObject)
Dim s As Socket = so.socket
Try
Dim read As Integer = s.EndReceive(ar)
If read > 0 Then
Dim frameCount = 2
Dim bytes As Byte() = so.buffer
printbytes(bytes, read)
End If
If (s.Connected = True) Then
s.BeginReceive(so.buffer, 0, SocketObject.BUFFER_SIZE, 0, New AsyncCallback(AddressOf Read_Callback), so)
Else
Me.Dispatcher.Invoke(Windows.Threading.DispatcherPriority.Background, New Delegate_LableAddText(AddressOf LableAddText), "-close-")
End If
Catch
End Try
End Sub
Public Delegate Sub Delegate_LableAddText(ByVal str As String)
''' <summary>
''' Check the received data and see if there is command from the device to check
''' </summary>
''' <param name="str"></param>
Public Sub LableAddText(ByVal str As String)
LblSock.Text += str
End Sub
Private Sub Button3_Click(sender As Object, e As RoutedEventArgs)
sock.socket.Close()
End Sub
Private Function random_sc_key() As String
Dim s As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
Dim r As New Random
Dim sb As New StringBuilder
For i As Integer = 0 To "gnuE6HbBVfsHzYVNLdxxbQ==".Length
Dim idx As Integer = r.Next(0, 35)
sb.Append(s.Substring(idx, 1))
Next
Dim a As String = sb.ToString()
Return "gnuE6HbBVfsHzYVNLdxxbQ=="
End Function
Private Sub BtnConnect_Click(sender As Object, e As RoutedEventArgs)
LblSock.Text = ""
'Set up variables and String to write to the server.
Dim ascii As Encoding = Encoding.UTF8
Dim request As String = "GET http://xxxxxxxxx.azurewebsites.net/xxxxxxxxx HTTP/1.1" + ControlChars.Cr + ControlChars.Lf + "Host: xxxxxxxxx.azurewebsites.net" + ControlChars.Cr + ControlChars.Lf + "Connection: Upgrade" + ControlChars.Cr + ControlChars.Lf + "Upgrade: WebSocket" + ControlChars.Cr + ControlChars.Lf + "Sec-WebSocket-Version: 13" + ControlChars.Cr + ControlChars.Lf + "Sec-WebSocket-Key: " + random_sc_key() + vbCrLf + vbCrLf
Dim bytesSent As [Byte]() = ascii.GetBytes(request)
Dim bytesReceived(255) As [Byte]
Dim hostEntry As IPHostEntry = Nothing
' Get host related information.
hostEntry = Dns.GetHostEntry("xxxxxxxxx.azurewebsites.net")
Dim address As IPAddress
For Each address In hostEntry.AddressList
Dim endPoint As New IPEndPoint(address, 80)
Dim tempSocket As New Socket(endPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp)
tempSocket.Connect(endPoint)
If tempSocket.Connected Then
sock.socket = tempSocket
Exit For
End If
Next address
If sock.socket Is Nothing Then
MessageBox.Show("Connection failed")
Exit Sub
End If
LblSock.Text += "Sending: " + request
' Send request to the server.
sock.socket.Send(bytesSent, bytesSent.Length, 0)
LblSock.Text += "BeginReceive" + vbCrLf
sock.socket.BeginReceive(sock.buffer, 0, SocketObject.BUFFER_SIZE, 0, New AsyncCallback(AddressOf Read_Callback), sock)
End Sub
Private Sub BtnSendString1_Click(sender As Object, e As RoutedEventArgs)
If (sock.socket.Connected = False) Then
LblSock.Text += vbCrLf + "connection closed" + vbCrLf
Exit Sub
End If
Dim request As String = txtsock.Text
request = "11" & request
Dim ascii As Encoding = Encoding.UTF8
Dim bytesSent As Byte() = ascii.GetBytes(request)
bytesSent(0) = &H81
bytesSent(1) = txtsock.Text.Length
LblSock.Text += vbCrLf + "Sending string: " + txtsock.Text
LblSock.Text += vbCrLf + "Sending bytes: "
Dim i As Int16
For i = 0 To bytesSent.Length - 1
LblSock.Text += bytesSent(i).ToString() + ","
Next
sock.socket.Send(bytesSent)
End Sub
Private Sub BtnCloseSock_Click(sender As Object, e As RoutedEventArgs)
If (sock.socket.Connected = False) Then
LblSock.Text += vbCrLf + "connection closed" + vbCrLf
Exit Sub
End If
Dim request As String = txtsock.Text
request = "1" & request & "1"
Dim ascii As Encoding = Encoding.UTF8
Dim bytesSent As Byte() = ascii.GetBytes(request)
bytesSent(0) = 0
'bytesSent(1) = txtsock.Text.Length
bytesSent(bytesSent.Length - 1) = &HFF
sock.socket.Send(bytesSent)
End Sub
【问题讨论】：
-
没有代码，很难帮助你......我预感我会说客户端没有正确编码 WebSocket 数据。您确定要根据客户端上的 WebSocket 协议对数据进行编码吗？您的客户是否正确屏蔽了数据？您是否将掩码附加在编码数据的头部（在数据包的头部之后和数据之前）？
-
附加代码，字符串是 UTF-8 编码的，我还添加了发送到服务器和从服务器发送的字节，它看起来类似于协议。但我仍然想念一些东西。
-
此行：
bytesSent(1) = txtsock.Text.Length仅对txtsock.Text.Length < 127有效。客户端似乎也没有屏蔽消息（客户端必须屏蔽，服务器不能屏蔽，存在编码差异）......再说一次，我对 VB.NET 没有任何好处。考虑将语言标签添加到您的问题中，也许您会得到更多的输入。 -
关于帧（
标签： websocket