In order to design unity and user operation, we hope to integrate the server with the client to form a program so that the user understands, it is more intuitive (in fact, it is also convenient to debug, everyone can test it on this machine Pass the file to yourself). So, we need to use two WINSOCK controls in the program, one responsible for listening, one responsible for sending, when the sender is successful, then select a file to be sent (can be any binary), then file name and file byte The length is sent to the receiving end. After receiving this message, the file name and file length are resolved, and then the sending end can start sending the file; send the file to this message, send the file to receive the file. After receiving the end, the binary stream is written back, and the file is saved. Here, pay attention to the two points, one is due to the maximum content of 8K each time, so you need to decompose files, each transfer fixed number of byte streams, which can determine the process of file transmission based on this number every time you send and receive. Once the number of byte streams is equal to the size of the file, it is necessary to close the corresponding file handle; the other is because I only use a Winsock control to receive, you need to pay attention to the unicode transcoding, parse the identifiable information when receiving text.
Source code
'The following code is both a server and a client.
'Uses a replysence sending method
'Auto split file, including 2
Option expedition
'Private Declare Sub Sleep LIB "Kernel32" (Byval dwmilliseconds as ring)
DIM mybyte () as byte 'sending a number group
Const filecomesmsg = "a file is coming" "has file arrival
Const remoteisreadymsg = "sender is ready" is ready
Const fileiSovermsg = "the file is ended" file is completed
Const Remotedenymsg = "The user cande" "user cancels
Const filecountmsg = "the file length is" file length
Const receveVieisreadymsg = "receiver is ready" is ready to receive
DIM Arrdata () as byte 'received information
DIM Filesave as integer 'Save the handle of the file
DIM FileHandle As INTEGER 'Handle of Sending File
DIM FILESIZE AS DOUBLE '
DIM Sendbyte As Long
Dim ReceivebyTe As Long
DIM MYLOCATION AS DOUBLE
DIM mymsg as string 'message
Does the DIM FILESOVER AS BOOLEAN 'file have been completed
Const receificport = 7905
Const buffer_size = 5734
Private sub cmdconnect_click ()
Timer2.enabled = TRUE
End Sub
Private subcmdsend_click ()
ON Error Goto Errorhandlewith CommonDialog1
.Cancelerror = true
.Dialogtitle = "Select the file you want to transfer"
.Filter = "all files (*. *) | *. *"
.Showopen
End with
FileHandle = freefile
Open Commondialog1.FileName for Binary Access Read as #fileHandle
cmdsend.enabled = false
FileSize = CDBL (Filelen (Commondialog1.FileName)
Label1.caption = "Wait for the response >>>"
Msgbox ("Selected File Size" & Lof (FileHandle) & "Byte")
IF Winsocksend.State = Sckconnected Then
Winsocksend.sendData filecomesmsmsg & commondialog1.filename 'Send file information
END IF
EXIT SUB
ErrorHandle:
cmdsend.enabled = true
Msgbox ("You didn't choose a file!")
End Sub
Private sub flow_load ()
WinsockReceive.localPort = ReceivePort
WinsockReceive.Listen
FILESOVER = TRUE
Label1.caption = "Prepare Transport >>>"
End Sub
Public function sendchunk ()
DIM MyBytesize As Long
IF Winsocksend.State <> SCKCONNECTED THEN EXIT FUNCTION
MyBytesize = buffer_size
If LOF (FileHandle) - LOC (FileHandle) Redim mybyte (0 to mybytesize - 1) Get #filehandle, Mybyte Winsocksend.senddata mybyte SendByte = sendbyte mybytesize ProgressBar1.Value = int ((100 / filesis) * sendbyte) IF sendbyte> = filesize kil FILESOVER = TRUE Winsocksend.senddata fileiSovermsg END IF END FUNCTION Private sub timer2_timer () IF Winsocksend.State = Sckconnected Then Timer2.enabled = false cmdconnect.enabled = false Elseif Winsocksend.State <> 1 and winsocksend.State <> 6 and winsocksend.state <> 7 and winsocksend.state <> 8 and winsocksend.state <> 9 thenwinsocksend.connect txthost.text, receivedport Elseif Winsocksend.State = 8 or Winsocksend.State = 9 THEN Winsocksend.close END IF End Sub Private Sub WinsockRecEceptRece_ConnectionRequest (Byval Requestid As Long) If WinsockRecEive.State <> Sckclosed Ten WinsockRecEceptive.close WinsockReceive.accept Requestid End Sub Private sub winsockreceive_dataarrival (byval bytestotal as long) Redim Arrdata (0 to Bytestotal - 1) WinsockReceive.getdata Arrdata, Vbbyte VBarray Mymsg = strconv (arrdata, vbunicode) 'binary turn to string SELECT CASE MID (Mymsg, 1, 17) Case filecomesmsg 'These message senders and acceptors can receive 'Display Save Dialog ON Error Goto Errorhandle CommonDialog1.filename = MID (Mymsg, 17, Len (MyMSG)) CommonDialog1.dialogtitle = "Select the path to save the file" CommonDialog1.showsave Filesave = freefile ReceiveByte = 0 cmdsend.enabled = false WinsockReceive.senddata Recevieisreadymsg Case fileiSovermsg Close #filesave Msgbox ("Document Transfer Success!") 'Everyone is processed cmdconnect.enabled = true cmdsend.enabled = true Label1.caption = "Prepare Transport >>>" ProgressBar1.Value = 0 WinsockReceive.senddata fileiSovermsg WinsockRecEceptive.close WinsockReceive.Listen Case filecountmsg FILESIZE = MID (MyMSG, 18, Len (MyMSG)) Open commitialog1.filename for binary access write #filesave WinsockReceive.senddata Remoteisreadymsg Label1.caption = "file ready to transfer!" FILESOVER = FALSE Case Else IF receivebyte ReceiveByte = ReceiveByte bytestotal Put #filesave, ArrdatawinsockRecEth.senddata Remoteisreadymsg ProgressBar1.Value = int ((100 / filesis) * ReceiveByte) END IF End SELECT EXIT SUB ErrorHandle: WinsockReceive.senddata Remotedenymsg cmdconnect.enabled = true End Sub Private sub winsocksend_dataarrival (Byval Bytestotal As Long) Winsocksend.getdata mymsg SELECT CASE MYMSG Case Recevieisreadymsg Winsocksend.senddata FileCountmsg & FileSize FILESOVER = FALSE Sendbyte = 0 Case Remoteisreadymsg 'If the file has not ended, continue to transfer IF not fileisover Label1.caption = "file is being transferred >>>" Sendchunk Else Winsocksend.senddata fileiSovermsg END IF Case fileiSovermsg 'Host processing Close #filehandle Msgbox ("Document Transfer Success!") 'Everyone is processed Winsocksend.senddata fileiSovermsg Winsocksend.close cmdconnect.enabled = true ProgressBar1.Value = 0 cmdsend.enabled = true Label1.caption = "Prepare Transport >>>" Case Remotedenymsg Msgbox ("User terminates the transfer!") cmdsend.enabled = true Label1.caption = "Prepare Transport >>>" Close #filehandle End SELECT EXIT SUB End Sub This program is WinXPSP1 VB6 with Win2000sp4 VB6 The following debugging is successful.
