我试过编写一个将文件拆分成较小部分的方法（我将这些部分称为“块”），我使用1 MB的缓冲区来读取/写入块，然后我报告操作进度百分比和当前的块进度百分比。
问题是这个，我有一个6,74 GB的大文件，我将它分成每个1 GB的块，进度报告按预期工作但不是最后一个块，其中进度仅为75 ％'因为当然最后一部分大约是750 mb而不是1 GB，那么进度只会在最后一个块中显示高达75％。
这就是我获取百分比的方法，错误的进度是ChunkProgress块中的Else值：
If Not ChunkIndex = ChunkCount Then
ProgressArguments =
New SplitProgressChangedArgs(
TotalProgress:=(TotalSize - SizeRemaining) * (100I / TotalSize),
ChunkProgress:=(100I / ChunkSize) * (SizeWritten - BufferLength),
ChunksToCreate:=ChunkCount + 1,
ChunksCreated:=ChunkIndex)
Else
ProgressArguments =
New SplitProgressChangedArgs(
TotalProgress:=(TotalSize - SizeRemaining) * (100I / TotalSize) - 1.0R,
ChunkProgress:=(100I / ChunkSize) * (SizeWritten - InputStream.Length),
ChunksToCreate:=ChunkCount + 1,
ChunksCreated:=ChunkIndex)
End If
TotalSize =要拆分的文件的固定大小，以字节为单位（在本例中为6,74 gb）
ChunkSize =块的固定大小，以字节为单位（在本例中为1 GB）
SizeRemaining =总剩余大小计数器，以字节为单位（在本例中为6,74 gb到0）。
SizeWritten =写入计数器的块大小，以字节为单位（在本例中为0到1 GB）
在写最后一块时，有人可以帮我修正百分比吗？
这是Class的相关代码：
''' <summary>
''' Gets or sets the buffer-size to split or merge, in Bytes.
''' Default value is: 1048576 bytes (1 megabyte).
''' </summary>
''' <value>The buffer-size.</value>
Public Property BufferSize As Integer = 1048576I
''' <summary>
''' Splits the specified file.
''' </summary>
''' <param name="InputFile">Indicates the file to split.</param>
''' <param name="ChunkSize">Indicates the size of each chunk.</param>
''' <param name="ChunkName">Indicates the name-format for the chunks.</param>
''' <param name="ChunkExt">Indicates the file-extension for the chunks.</param>
''' <param name="Overwrite">
''' If set to <c>true</c> any existing file will be overwritten if needed to create a chunk,
''' otherwise, an exception will be thrown.
''' </param>
''' <param name="DeleteAfterSplit">If set to <c>true</c> the input file will be deleted after a successful split.</param>
''' <exception cref="System.OverflowException">'ChunkSize' should be smaller than the Filesize.</exception>
''' <exception cref="System.IO.IOException">File already exist</exception>
Public Sub Split(ByVal InputFile As String,
ByVal ChunkSize As Long,
Optional ByVal ChunkName As String = Nothing,
Optional ByVal ChunkExt As String = Nothing,
Optional ByVal Overwrite As Boolean = False,
Optional ByVal DeleteAfterSplit As Boolean = False)
' The progress event arguments.
Dim ProgressArguments As SplitProgressChangedArgs
' FileInfo instance of the input file.
Dim fInfo As New FileInfo(InputFile)
' The total filesize to split, in bytes.
Dim TotalSize As Long = fInfo.Length
' The remaining size to calculate the percentage, in bytes.
Dim SizeRemaining As Long = TotalSize
' Counts the length of the current chunk file to calculate the percentage, in bytes.
Dim SizeWritten As Long = 0L
' The buffer to read data and write the chunks.
Dim Buffer As Byte() = New Byte() {}
' The buffer length.
Dim BufferLength As Integer = Me.BufferSize
' The total amount of chunks to create.
Dim ChunkCount As Integer = CInt(Math.Floor(fInfo.Length / ChunkSize))
' Keeps track of the current chunk.
Dim ChunkIndex As Integer = 0I
' A zero-filled string to enumerate the chunk files.
Dim Zeros As String = String.Empty
' The given filename for each chunk.
Dim ChunkFile As String = String.Empty
' The chunk file basename.
ChunkName = If(String.IsNullOrEmpty(ChunkName),
Path.Combine(fInfo.DirectoryName, Path.GetFileNameWithoutExtension(fInfo.Name)),
Path.Combine(fInfo.DirectoryName, ChunkName))
' The chunk file extension.
ChunkExt = If(String.IsNullOrEmpty(ChunkExt),
fInfo.Extension.Substring(1I),
ChunkExt)
' If ChunkSize is bigger than filesize then...
If ChunkSize >= fInfo.Length Then
Throw New OverflowException("'ChunkSize' should be smaller than the Filesize.")
Exit Sub
' For cases where a chunksize is smaller than the buffersize.
ElseIf ChunkSize < BufferLength Then
BufferLength = CInt(ChunkSize)
End If ' ChunkSize <>...
' If not file-overwrite is allowed then...
If Not Overwrite Then
For Index As Integer = 0I To (ChunkCount)
' Set chunk filename.
Zeros = New String("0", CStr(ChunkCount).Length - CStr(Index + 1I).Length)
ChunkFile = String.Format("{0}.{1}.{2}", ChunkName, Zeros & CStr(Index + 1I), ChunkExt)
' If chunk file already exists then...
If File.Exists(ChunkFile) Then
Throw New IOException(String.Format("File already exist: {0}", ChunkFile))
Exit Sub
End If ' File.Exists(ChunkFile)
Next Index
Zeros = String.Empty
ChunkFile = String.Empty
End If ' Overwrite
' Open the file to start reading bytes.
Using InputStream As New FileStream(fInfo.FullName, FileMode.Open)
Using BinaryReader As New BinaryReader(InputStream)
While (InputStream.Position < InputStream.Length)
' Set chunk filename.
Zeros = New String("0", CStr(ChunkCount).Length - CStr(ChunkIndex + 1I).Length)
ChunkFile = String.Format("{0}.{1}.{2}", ChunkName, Zeros & CStr(ChunkIndex + 1I), ChunkExt)
' Reset written byte-length counter.
SizeWritten = 0L
' Create the chunk file to Write the bytes.
Using OutputStream As New FileStream(ChunkFile, FileMode.Create)
Using BinaryWriter As New BinaryWriter(OutputStream)
' Read until reached the end-bytes of the input file.
While (SizeWritten < ChunkSize) AndAlso (InputStream.Position < InputStream.Length)
' Read bytes from the original file (BufferSize byte-length).
Buffer = BinaryReader.ReadBytes(BufferLength)
' Write those bytes in the chunk file.
BinaryWriter.Write(Buffer)
' Increment the bytes-written counter.
SizeWritten += Buffer.Count
' Decrease the bytes-remaining counter.
SizeRemaining -= Buffer.Count
If Not ChunkIndex = ChunkCount Then
ProgressArguments =
New SplitProgressChangedArgs(
TotalProgress:=(TotalSize - SizeRemaining) * (100I / TotalSize),
ChunkProgress:=(100I / ChunkSize) * (SizeWritten - BufferLength),
ChunksToCreate:=ChunkCount + 1,
ChunksCreated:=ChunkIndex)
Else
ProgressArguments =
New SplitProgressChangedArgs(
TotalProgress:=(TotalSize - SizeRemaining) * (100I / TotalSize) - 1.0R,
ChunkProgress:=(100I / ChunkSize) * (SizeWritten - InputStream.Length),
ChunksToCreate:=ChunkCount + 1,
ChunksCreated:=ChunkIndex)
End If
' Report the progress.
RaiseEvent SplitProgressChanged(Me, ProgressArguments)
End While ' (SizeWritten < ChunkSize) AndAlso (InputStream.Position < InputStream.Length)
OutputStream.Flush()
End Using ' BinaryWriter
End Using ' OutputStream
ChunkIndex += 1I 'Increment the chunk file counter.
End While ' InputStream.Position < InputStream.Length
End Using ' BinaryReader
End Using ' InputStream
End Sub
这是一个示例用法：
Splitter.Split(InputFile:="C:\Test.mkv",
ChunkSize:=1073741824L,
ChunkName:="Test.Part",
ChunkExt:="mp3",
Overwrite:=True,
DeleteAfterSplit:=False)
答案 0 :(得分：1)
进度没有在最后一个块上正确显示的原因是因为你正在计算正常＆＃34;正常＆＃34;块大小
例如（简化值）：
500 out of 1000 bytes with ChunkSize = 1000
500 / ChunkSize = %
500/1000 = 0.5
如果最后一个块只有750个字节，我们必须通过除(thisChunk / ChunkSize)来纠正：
500 out of 750 bytes with ChunkSize = 1000
500 / ChunkSize / (thisChunk / ChunkSize) = %
500/1000 / (750/1000) = 0.667
请针对Else案例进行尝试。 (InputStream.Length - SizeWritten)应该获得剩余块的大小：
ProgressArguments =
New SplitProgressChangedArgs(
TotalProgress:=(TotalSize - SizeRemaining) * (100I / TotalSize) - 1.0R,
ChunkProgress:=(100I / ChunkSize) * (SizeWritten - InputStream.Length) / ((InputStream.Length - SizeWritten) / ChunkSize),
ChunksToCreate:=ChunkCount + 1,
ChunksCreated:=ChunkIndex)