Как отправлять и получать скриншоты непрерывно с помощью асинхронного сокетного программирования? - PullRequest
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Как отправлять и получать скриншоты непрерывно с помощью асинхронного сокетного программирования?

1 голос
/ 05 марта 2020

У меня есть цель непрерывно отправлять и получать скриншоты, используя асинхронный сокет, и создал следующий код после просмотра нескольких ссылок в Интернете. Перед попыткой отправки постоянно я проверял отправку только один раз, но скриншот не был получен правильно на сервере.

Некоторые идеи о том, как это исправить? Заранее спасибо.

Сервер: 

Imports System.IO
Imports System.Net
Imports System.Net.Sockets
Imports System.Text

Public Class frmServer
    Dim serverSocket As Socket
    Dim clientSocket As Socket
    Dim byteData(1023) As Byte

    Private Sub FrmServer_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        serverSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        Dim IpEndPoint As IPEndPoint = New IPEndPoint(IPAddress.Any, 8800)
        serverSocket.Bind(IpEndPoint)
        serverSocket.Listen(5)
        serverSocket.BeginAccept(New AsyncCallback(AddressOf OnAccept), Nothing)
    End Sub

    Private Sub OnAccept(ByVal ar As IAsyncResult)
        clientSocket = serverSocket.EndAccept(ar)
        'New connection established
        clientSocket.BeginReceive(byteData, 0, byteData.Length, SocketFlags.None, New AsyncCallback(AddressOf OnReceive), clientSocket)
        serverSocket.BeginAccept(New AsyncCallback(AddressOf OnAccept), Nothing)
    End Sub

    Private Sub OnReceive(ByVal ar As IAsyncResult)
        Dim client As Socket = ar.AsyncState
        client.EndReceive(ar)

        'Using MStream As New MemoryStream(byteData)
        'Dim returnImage As Image = Image.FromStream(MStream)
        'pbDesktop.Image = returnImage
        'End Using

        File.WriteAllBytes(Environment.CurrentDirectory & "\screenshot.jpg", byteData)

        'Array.Clear(byteData, 0, byteData.Length)
        clientSocket.BeginReceive(byteData, 0, byteData.Length, SocketFlags.None, New AsyncCallback(AddressOf OnReceive), clientSocket)
    End Sub

Клиент: 

Imports System.Drawing.Imaging
Imports System.IO
Imports System.Net
Imports System.Net.Sockets

Public Class frmClient

    Private Function BytesScreen() As Byte()
        Dim bounds As Rectangle
        Dim screenshot As Bitmap
        Dim graph As Graphics
        bounds = Screen.PrimaryScreen.Bounds
        screenshot = New Bitmap(bounds.Width, bounds.Height)
        graph = Graphics.FromImage(screenshot)
        graph.CopyFromScreen(bounds.X, bounds.Y, 0, 0, bounds.Size, CopyPixelOperation.SourceCopy)

        Dim ms As New MemoryStream()
        screenshot.Save(ms, ImageFormat.Jpeg)
        Dim bitmapbytestream(ms.Length) As Byte
        bitmapbytestream = ms.ToArray

        Return bitmapbytestream
    End Function

    Dim clientSocket As Socket

    Private Sub BtnConnect_Click(sender As Object, e As EventArgs) Handles btnConnect.Click
        clientSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        Dim IpAddress As IPAddress = IPAddress.Parse("127.0.0.1")
        Dim IpEndPoint As IPEndPoint = New IPEndPoint(IpAddress, 8800)
        clientSocket.BeginConnect(IpEndPoint, New AsyncCallback(AddressOf OnConnect), Nothing)
    End Sub

    Private Sub OnConnect(ByVal ar As IAsyncResult)
        clientSocket.EndConnect(ar)
        Send(BytesScreen, clientSocket)
    End Sub

    Private Sub Send(ByVal byteData As Byte(), ByVal client As Socket)
        Try
            client.BeginSend(byteData, 0, byteData.Length, SocketFlags.None, New AsyncCallback(AddressOf OnSend), client)
        Catch ex As Exception
            If Not client.Connected Then 'if connection was forcibly disconnected
                'reconnecting to the server
                btnConnect.PerformClick()
            End If
        End Try
    End Sub

    Private Sub OnSend(ByVal ar As IAsyncResult)
        Dim client As Socket = ar.AsyncState
        client.EndSend(ar)
        'Send(BytesScreen, clientSocket)
    End Sub

End Class
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