Visual Basic - Send File With Winsock

[DigiRev]

Just a small code snippet to transfer the contents of a file over a Winsock connection (the socket must first be connected). Here is a brief description of the parameters:

SendFile(SocketObject As Variant, FilePath As String, PacketSize As Long)

• SocketObject - The winsock control you will be using to send the file. It is passed as a variant so you can use a winsock control that is part of an array, or one that isn't.
• FilePath - The full path to the file you are sending.
• PacketSize - The amount of data to send at once, or in one packet. The file is sent in seperate chunks, and this specifies how many bytes to send at a time. For slower connections, like 56k, you will want to make this a small number, like 512 (1/2 KB) or 1024 (1 KB). For high speed internet connections you can make it much larger.

Public Sub SendFile(SocketObject As Variant, ByVal FilePath As String, ByVal PacketSize As Long)
Dim lonFF As Long, bytData() As Byte
Dim lonCurByte As Long, lonSize As Long
Dim lonPrevSize As Long

On Error GoTo ErrorHandler

lonSize = FileLen(FilePath)

Open FilePath For Binary Access Read As #lonFF
    
    ReDim bytData(1 To PacketSize) As Byte
    
    Do Until (lonSize - lonCurByte) < PacketSize
        Get #lonFF, lonCurByte + 1, bytData()
        lonCurByte = lonCurByte + PacketSize
        SocketObject.senddata bytData()
        DoEvents
    Loop
    
    lonPrevSize = lonSize - lonCurByte
    
    If lonPrevSize > 0 Then
        ReDim bytData(1 To lonPrevSize) As Byte
        Get #lonFF, lonCurByte + 1, bytData()
        lonCurByte = lonCurByte + lonPrevSize
        SocketObject.senddata bytData()
    End If

Close #lonFF
Exit Sub

ErrorHandler:
    Debug.Print "Send File Error"
    Debug.Print "---------------"
    Debug.Print "Number:      " & Err.Number
    Debug.Print "Description: " & Err.Description
    Debug.Print "File:        " & FilePath
    
End Sub