Question

vb6.0怎么用winsock发送大文件

像传输1G的电影，怎么弄？
Private Sub Command2_Click()

Dim a() As Byte
If Winsock1.State = sckClosed Then
MsgBox "错误", vbCritical, "Alert"
Exit Sub
End If

y = InputBox("请输入文件类型", "")
CommonDialog1.Filter = "*." & y
CommonDialog1.ShowOpen
If CommonDialog1.FileName = "" Then
Exit Sub
End If

send_filename = CommonDialog1.FileName

Open send_filename For Binary As #1
If LOF(1) <= 1012 Then
ReDim a(LOF(1) - 1) As Byte
Get #1, , a
Winsock1.SendData a
Close
Exit Sub
End If

If LOF(1) > 1012 Then
lump = LOF(1) \ 1012
left_lump = LOF(1) Mod 1012
For i = 1 To lump
ReDim a(1 To 1012) As Byte
Get #1, , a
Winsock1.SendData a
Next
Exit Sub
End If

If left_lump > 0 Then
ReDim a(1 To left_lump) As Byte
Get #1, , a
Winsock1.SendData a
End If
Close
Exit Sub
End Sub
这是我的发送端的代码，怎么改？

Answer 1

这跟文件大小有什么关系。用内存映射技术读取大文件，用tcp协议的socket发送出去，多大的都没问题。要注意映射块的剩余量问题，不够一次发送量时要先暂存，读取下一映射块后再发送。这样实现可以达到局域网的最大带宽速度。如果偷懒使用win api，速度可能就几m而已。

追问

那怎么弄啊？能给个代码吗？谢谢

追答

没有vb的例子，只有c++的，贴出来也没用。你看看这个，也许合用，这种事vb不是强项：
http://wenku.baidu.com/view/3989521810a6f524ccbf8566.html

Answer 2

'读一段发一段，直到结束，使用2进制读取文件，每读取一段发送成功后指针向后移动sendfilesize再读取，当然中间要加eof判断
Const sendfilesize = 1024 '发送文件块大小
Private Sub Command1_Click()
Dim a() As Byte
ReDim a(sendfilesize)

End Sub

追问

DoEvents
Dim a() As Byte
accept_filename = App.Path & "\" & App.EXEName & ".txt"
Open accept_filename For Binary As #1
If LOF(1) = 0 Then
List1.AddItem "数据到达lof(1)=0: " & bytesTotal
ReDim a(bytesTotal - 1)
Winsock1.GetData a
Put #1, 1, a
Else
List1.AddItem "数据到达lof(1)0: " & bytesTotal
ReDim a(bytesTotal - 1)
Winsock1.GetData a
Put #1, LOF(1) + 1, a
End If
Close
怎么改？