'VB 实现大文件的分割与恢复,引用 ADODB.Stream 提供一个过程:
'要引用 Microsoft ActiveX Data Objects 2.5 Libary
'或 Microsoft ActiveX Data Objects 2.6 Libary
Public Sub StreamSplit(SourceFile As String, DestinationFile As String, ChunkSize As Long, Optional BufferSize As Long = 64# * 1024#, Optional ShowFinishMessage As Boolean)
'ChunkSize 为 BufferSize 的倍数
Dim adoStreamS As New ADODB.Stream
adoStreamS.Type = adTypeBinary
adoStreamS.Open
adoStreamS.LoadFromFile SourceFile
Dim lFileSize As Long
lFileSize = adoStreamS.Size
Dim i As Long
Dim adoStreamT As New ADODB.Stream
adoStreamT.Type = adTypeBinary
Do While lFileSize >= ChunkSize * BufferSize
adoStreamT.Open
adoStreamT.Write adoStreamS.Read(ChunkSize * BufferSize)
adoStreamT.SaveToFile DestinationFile & "." & Format(i, "000"), IIf(Len(Trim(Dir(DestinationFile & "." & Format(i, "000")))) > 0, adSaveCreateOverWrite, adSaveCreateNotExist)
adoStreamT.Close
lFileSize = lFileSize - ChunkSize * BufferSize
i = i + 1
Loop
If lFileSize > 0 Then
adoStreamT.Open
adoStreamT.Write adoStreamS.Read(lFileSize)
adoStreamT.SaveToFile DestinationFile & "." & Format(i, "000"), IIf(Len(Trim(Dir(DestinationFile & "." & Format(i, "000")))) > 0, adSaveCreateOverWrite, adSaveCreateNotExist)
End If
If ShowFinishMessage Then
MsgBox "Finished!"
End If
End Sub
Public Sub StreamRestore(SourceFile As String, DestinationFile As String, Chunks As Long, Optional BufferSize As Long = 64# * 1024#, Optional ShowFinishMessage As Boolean)
Dim lFileSize As Long
Dim adoStreamT As New ADODB.Stream
adoStreamT.Type = adTypeBinary
adoStreamT.Open
Dim adoStreamS As New ADODB.Stream
adoStreamS.Type = adTypeBinary
Dim i As Long
For i = 0 To Chunks - 1 'Chunks 块数
adoStreamS.Open
adoStreamS.LoadFromFile SourceFile & "." & Format(i, "000")
adoStreamT.Write adoStreamS.Read
adoStreamS.Close
Next i
adoStreamT.SaveToFile DestinationFile, IIf(Len(Trim(Dir(DestinationFile))) > 0, adSaveCreateOverWrite, adSaveCreateNotExist)
If ShowFinishMessage Then
MsgBox "Finished!"
End If
End Sub
'VB 实现大文件的分割与恢复,采用读写二进制数据的传统经典代码:
Public Sub FileSplit(SourceFile As String, DestinationFile As String, ChunkSize As Long, Optional BufferSize As Long = 64# * 1024#, Optional ShowFinishMessage As Boolean)
'ChunkSize 为 BufferSize 的倍数
Dim FileBuffer() As Byte
Dim FileNumberS As Long
Dim FileNumberT As Long
FileNumberS = FreeFile
Open SourceFile For Binary Access Read As #FileNumberS
Dim lFileLen As Long
lFileLen = FileLen(SourceFile)
FileNumberT = FreeFile
Dim i As Long
Dim j As Long
ReDim FileBuffer(1 To (BufferSize)) As Byte
Open DestinationFile & "." & Format(i, "000") For Binary Access Write As #FileNumberT
Do While lFileLen >= BufferSize
Get #FileNumberS, , FileBuffer
If i = ChunkSize Then
i = 0
j = j + 1
Close #FileNumberT
FileNumberT = FreeFile
Open DestinationFile & "." & Format(j, "000") For Binary Access Write As #FileNumberT
End If
i = i + 1
Put #FileNumberT, , FileBuffer
lFileLen = lFileLen - BufferSize
Loop
If lFileLen > 0 Then
ReDim FileBuffer(1 To lFileLen) As Byte
Get #FileNumberS, , FileBuffer
Put #FileNumberT, , FileBuffer
End If
Close #FileNumberT
If ShowFinishMessage Then
MsgBox "Finished!"
End If
End Sub
Public Sub FileRestore(SourceFile As String, DestinationFile As String, Chunks As Long, Optional BufferSize As Long = 64# * 1024#, Optional ShowFinishMessage As Boolean)
Dim FileBuffer() As Byte
Dim FileNumberS As Long
Dim FileNumberT As Long
Dim i As Long
Dim lFileLen As Long
FileNumberT = FreeFile
Open DestinationFile For Binary Access Write As #FileNumberT
For i = 0 To Chunks - 1
FileNumberS = FreeFile
Open SourceFile & "." & Format(i, "000") For Binary Access Read As #FileNumberS
lFileLen = FileLen(SourceFile & "." & Format(i, "000"))
ReDim FileBuffer(1 To BufferSize) As Byte
Do While lFileLen >= BufferSize
Get #FileNumberS, , FileBuffer
Put #FileNumberT, , FileBuffer
lFileLen = lFileLen - BufferSize
Loop
If lFileLen > 0 Then
ReDim FileBuffer(1 To lFileLen) As Byte
Get #FileNumberS, , FileBuffer
Put #FileNumberT, , FileBuffer
End If
Close #FileNumberS
Next i
Close #FileNumberT
If ShowFinishMessage Then
MsgBox "Finished!"
End If
End Sub