Vb.net 等待发生事件的单元

我试图生成一个等待事件发生的代码。我使用本页中的答案进行Tcp通信。当收到数据包时，将引发

事件
PacketReceived

Private Sub FooBar()
    'Send some Tcp Message here`

    'Wait until a reply is received here

    'Execute some code when reply is received

End Sub

这是发送文件名和文件用途的代码。它缺乏文件存在性检查

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        Dim t = New Thread(AddressOf SendFile)
        Dim f = New FileAndData
        f.FileList = SlideShowItems
        f.FileType = "tempSlideShowImage"
        t.Start(f)
    End Sub

    Private Sub SendFile(obj As Object)
        Dim fD = CType(obj, FileAndData)
        For Each item In fD.FileList.Items
            Dim fileIn As New FileStream(item, FileMode.Open)
            Const chunkSize = 10485760

            Dim messageFileNamePkt As New TcpMessagePacket(Encoding.Default.GetBytes(Path.GetFileName(item)), TcpMessagePacket.PacketHeader.Filename)
            messageFileNamePkt.Send(_etcClient.Client) 'Send file name

            Dim messageFiletype As New TcpMessagePacket(Encoding.Default.GetBytes(fD.FileType), TcpMessagePacket.PacketHeader.Filetype)
            messageFiletype.Send(_etcClient.Client) 'Send file type

            'Wait here for reply if for file existence

            While fileIn.Position < fileIn.Length
                Dim bytes(chunkSize) As Byte
                If fileIn.Length - fileIn.Position < bytes.Length Then
                    ReDim bytes(fileIn.Length - fileIn.Position - 1)
                End If
                fileIn.Read(bytes, 0, bytes.Length)

                Dim messageFilePkt As New TcpMessagePacket(bytes, TcpMessagePacket.PacketHeader.FileData)
                messageFilePkt.Send(_etcClient.Client) 'Send file chunks

            End While

            fileIn.Close()
            Dim messageFileEnd As New TcpMessagePacket(Encoding.Default.GetBytes(""), TcpMessagePacket.PacketHeader.TransferComplete)
            messageFileEnd.Send(_etcClient.Client) 'Send transfer complete

        Next
    End Sub

Public Class FileAndData
    Public FileList As ListBox
    Public FileType As String
End Class

使用
。前

Imports System.Threading
Module Module1
    Private ReadOnly WaitEvent As New ManualResetEvent(True)
    Sub Main()
        For i = 1 To 100
            WaitEvent.WaitOne() 'This is like a door. It's open because of ManualResetEvent(True)
            If i = 50 Then
                WaitEvent.Reset() 'This closes the door
            End If
            Console.WriteLine(i)
        Next
        Console.Read()
    End Sub
    Private Sub SetTheEventWhenCalled()
        WaitEvent.Set() 'This on the other hand, Opens the door
    End Sub
End Module

你好！这是我在这里的代码的一个很好的实现，但是有两件事我想指出，这可能会使它更有效率：1）10485760字节（10 MB）的块大小非常需要为每次发送放入网络缓冲区，并且很可能会大大降低速度通过我自己的测试，我发现理想的缓冲区大小是8192-32768（8-32KB）——甚至在局域网上也是如此。高于或低于这些值的所有内容都会导致发送速度大大减慢。（必须将其拆分为两条注释）：2）当发送没有数据的数据包时，而不是使用
编码。Default.GetBytes（“”）
只需执行以下操作：
newbyte（）{}
即可创建空字节数组。两者之间的执行速度差异可能只有几百微秒到一毫秒，但这仍然是一种改进，消除了不必要的处理。
Imports System.Threading
Module Module1
    Private ReadOnly WaitEvent As New ManualResetEvent(True)
    Sub Main()
        For i = 1 To 100
            WaitEvent.WaitOne() 'This is like a door. It's open because of ManualResetEvent(True)
            If i = 50 Then
                WaitEvent.Reset() 'This closes the door
            End If
            Console.WriteLine(i)
        Next
        Console.Read()
    End Sub
    Private Sub SetTheEventWhenCalled()
        WaitEvent.Set() 'This on the other hand, Opens the door
    End Sub
End Module