I'm trying to import and convert from various sources in c# for create a web-server. The configuration is this:
Development platform: VS Community in 2015
Type of application: VB / Windows IoT Core / Background Application
Hardware: Raspberry Pi 3
OS: Windows 10 IoT (v. 10.0.14393.693)
In some cases it is unable to send the page output. But in any case (even if it display the output), the page continues to load up to the crash of the application or stays in an endless loop.
The task
Public NotInheritable Class StartupTask
Implements IBackgroundTask
Private _Deferral As BackgroundTaskDeferral
Public Async Sub Run(taskInstance As IBackgroundTaskInstance) Implements IBackgroundTask.Run
taskInstance.GetDeferral()
Dim server As New webServer()
Await Windows.System.Threading.ThreadPool.RunAsync(AddressOf server.Start)
End Sub
End Class
The class of webserver
Imports System.Text
Imports Windows.Networking.Sockets
Imports Windows.Storage.Streams
Friend Class webServer
Private Const BufferSize As UInteger = 8192
Public Async Sub Start()
Try
Dim listener As New StreamSocketListener()
Debug.WriteLine("Debug: 1.1")
Await listener.BindServiceNameAsync("8081").AsTask()
Debug.WriteLine("Debug: 1.2")
AddHandler listener.ConnectionReceived, Async Sub(sender, args)
Debug.WriteLine("Debug: 2")
Dim request As New StringBuilder()
Using input As IInputStream = args.Socket.InputStream
Dim data As Byte() = New Byte(BufferSize - 1) {}
Dim buffer As IBuffer = data.AsBuffer()
Dim dataRead As UInteger = BufferSize
While dataRead = BufferSize
Await input.ReadAsync(buffer, BufferSize, InputStreamOptions.[Partial])
request.Append(Encoding.UTF8.GetString(data, 0, data.Length))
dataRead = buffer.Length
Debug.WriteLine("Debug: 2.2 - " & request.ToString)
End While
End Using
Debug.WriteLine("Debug: 3")
Using output As IOutputStream = args.Socket.OutputStream
Debug.WriteLine("Debug: 3.1")
Using response As Stream = output.AsStreamForWrite()
Debug.WriteLine("Debug: 3.2")
Dim page As String = ""
Dim folder = Package.Current.InstalledLocation
Dim file = Await folder.GetFileAsync("index.html")
Dim readFile = Await Windows.Storage.FileIO.ReadLinesAsync(file)
For Each line In readFile
page += line
Next
Debug.WriteLine("Debug: 3.3 - " & page)
Dim bodyArray As Byte() = Encoding.UTF8.GetBytes(page)
Dim bodyStream = New MemoryStream(bodyArray)
Debug.WriteLine("Debug: 3.4")
Dim header = "HTTP/1.1 200 OK" & vbCr & vbLf + "Content-Length: {bodyStream.Length}" & vbCr & vbLf + "Connection: close" & vbCr & vbLf & vbCr & vbLf
Dim headerArray As Byte() = Encoding.UTF8.GetBytes(header)
Debug.WriteLine("Debug: 3.5")
Await response.WriteAsync(headerArray, 0, headerArray.Length)
Debug.WriteLine("Debug: 3.6")
Await bodyStream.CopyToAsync(response)
Debug.WriteLine("Debug: 3.7")
Await response.FlushAsync()
Debug.WriteLine("Debug: 3.8")
End Using
End Using
Debug.WriteLine("Debug: 4")
End Sub
Debug.WriteLine("Debug: 1.3")
Catch generatedExceptionName As Exception
Debug.WriteLine("Error: " & generatedExceptionName.Message)
End Try
End Sub
End Class
The Manifest
<Capabilities>
<Capability Name="internetClient" />
<Capability Name="internetClientServer" />
<Capability Name="privateNetworkClientServer" />
</Capabilities>
Debug output
Debug: 1.1
Debug: 1.2
Debug: 1.3
Debug: 2
Debug: 2.2 - GET /index.html HTTP/1.1 Host: 192.168.1.146:8081 Connection: keep-alive (and all the header...)
Debug: 3
Debug: 3.1
Debug: 3.2
Debug: 3.3 - Baro Raspy WIoT Hello world :D
Debug: 3.4
Debug: 3.5
Debug: 3.6
Debug: 3.7
Debug: 3.8
Debug: 4
Il thread 0x64c è terminato con il codice 0 (0x0).
Il thread 0xcfc è terminato con il codice 0 (0x0).
I suppose I did something wrong with the asynchronous thread but I just can not understand.
Thanks in advance
I found the problem myself.
The http header format was wrong. During the conversion from c# to vb I don't change this {bodyStream.Length} in the vb variable.
From this
Dim header = "HTTP/1.1 200 OK" & vbCr & vbLf + "Content-Length: {bodyStream.Length}" & vbCr & vbLf + "Connection: close" & vbCr & vbLf & vbCr & vbLf
To this
Dim header = "HTTP/1.1 200 OK" & vbCr & vbLf + "Content-Length: " & bodyStream.Length & vbCr & vbLf + "Connection: close" & vbCr & vbLf & vbCr & vbLf
Now I just hope that this code will be usefull to someone, at least I will not have lost so much time unnecessarily :)