Question

我在VB.Net中创建了一个文件共享程序，但是当我尝试发送文件时，接收部分没有正确接收文件。只是我发送的文件的一部分。说，我发送了100 MB文件，只收到10 MB。有时22 KB，39 MB等。接收文件的大小并不总是相同。您认为这会导致什么问题？如何正确接收整个文件？

发送部分

Sub Main()
    Dim ip As New IPEndPoint(IPAddress.Any, 8888)' Port Server
    Dim sock As New Sockets.Socket(AddressFamily.InterNetwork, SocketType.Stream,   ProtocolType.IP)' Protocol type
    sock.Bind(ip)
    sock.Listen(100)
    While True' Check Client Connection
        Try
           msg("Accept Client Connect")
           Dim csock As Sockets.Socket = sock.Accept
           Dim csend(1024 * 10000) As Byte
           Dim path As String = "C:\Users\IT\Desktop\test\" ' Location to save file
           Dim bLen As Integer = csock.Receive(csend) ' Byte Read Len
           Dim fileLen As Integer = BitConverter.ToInt32(csend, 0) ' File Len
           Dim fName As String = Encoding.ASCII.GetString(csend, 4, fileLen) ' File Name
           msg("Start Receive....." & fName)
           Dim bWrite As New BinaryWriter(File.Open(path + fName, FileMode.Append))
           bWrite.Write(csend, 4 + fileLen, bLen - 4 - fileLen)
           msg("File receiced and Save " & path)
           bWrite.Close()
           csock.Close()
       Catch ex As Exception
           msg(ex.Message)
       End Try
    End While
    Console.ReadLine()
End Sub

Sub msg(ByVal mesg As String)
mesg.Trim()
Console.WriteLine(" >> " + mesg)
End Sub

接收部分

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)     Handles Button2.Click
    Dim ipServer As IPAddress() = Dns.GetHostAddresses("127.0.0.1") ' IP Server
    Dim ip As IPEndPoint = New IPEndPoint(ipServer(0), 8888)
    Dim csock As Socket = New Socket(AddressFamily.InterNetwork, SocketType.Stream,     ProtocolType.IP)
    Dim fName As String = TextBox1.Text
    Dim path As String = TextBox2.Text
    Dim fNameByte() As Byte = Encoding.ASCII.GetBytes(fName)
    Dim fData() As Byte = File.ReadAllBytes(path & "\" & fName)
    Dim cData(4 + fName.Length + fData.Length) As Byte
    Dim fDataLen() As Byte = BitConverter.GetBytes(fNameByte.Length)
    Try
       fDataLen.CopyTo(cData, 0)
       fNameByte.CopyTo(cData, 4)
       fData.CopyTo(cData, 4 + fNameByte.Length)
       csock.Connect(ip)
       csock.Send(cData)
       MsgBox("Success Send File ")
       csock.Close()
    Catch ex As Exception
       MsgBox(ex.Message)
    End Try
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)  Handles Button1.Click
    If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
    TextBox1.Text = System.IO.Path.GetFileName(OpenFileDialog1.FileName)
    TextBox2.Text = System.IO.Path.GetDirectoryName(OpenFileDialog1.FileName)
    End If
End Sub

Answer 1

错误1， a使用附加模式创建了二进制文件，该模式应为创建 第07行

错误2，应该使用嵌套循环来接收数据包。在这里我添加do~循环。如果条件检查天气是另一个数据包可用或不通过检查它的大小，如果size = 0然后退出循环 第08~13行

错误3，当收到第一个数据包时，它被写入文件中减去元数据。比如bWrite.Write（csend，4 + fileLen，bLen-4-fileLen）。 在第06/10行 这对于第一个数据包是好的，但对于剩余的数据包没有因为元数据在开始时只发送一次，所以不应该从每个数据包中删除它。保留值应为0，并且在这种情况下包的长度为bLen。正如您在 第12行 所见，我将重置这些值。

         01,   Dim csock As Sockets.Socket = sock.Accept
         02,   Dim csend(1024 * 10000) As Byte
         03,   Dim bLen As Integer = csock.Receive(csend) ' Byte Read Len
         04,   Dim fileLen As Integer = BitConverter.ToInt32(csend, 0) ' File Len
         05,   Dim fName As String = Encoding.ASCII.GetString(csend, 4, fileLen) ' File Name
         06,   Dim strt As Integer = 4 + fileLen, ln As Integer = bLen - 4 - fileLen

         07,   Dim bWrite As New BinaryWriter(File.Open(path + fName, FileMode.Create))
         08,   Do
         09,       If bLen = 0 Then Exit Do
         10,       bWrite.Write(csend, strt, ln)
         11,       bLen = csock.Receive(csend) ' Byte Read Len
         12,       strt = 0 : ln = bLen
         13,   Loop

抱歉，我尽力解释它。

VB.Net文件传输：未完成的已接收文件

1 个答案: