使用进度条将同一文件复制到多个位置/驱动器

Question

我正在尝试制作一个旨在将一个文件同时复制到多个位置的 vb.net 应用程序。但是我不知道如何停止我收到的 System.IO.IOException 因为多个线程正在尝试访问该文件。这是我当前的代码：

Dim parts As String() = targ.Split(New Char() {"\"c})
Dim filename As String = parts(parts.Count - 1) 'target folder name
Dim dir_path As String = "" 'directory without target folder name
Dim FolderList As New List(Of String)
Dim copied As Integer = 0<

For f As Integer = 0 To parts.Count - 2
    dir_path += parts(f) + "\"
Next

Dim counter As Integer = IO.Directory.GetFiles(targ, "*.*", IO.SearchOption.AllDirectories).Length 'counts the number of files
newitm.SubItems(4).Text = "Copied (0/" + counter.ToString + ")" 'displays the amount of copied files
FolderList.Add(targ) 'Set first folder

Do While True
    Dim FoldersInsideDirectory As New List(Of String)
    If FolderList.Count = 0 Then
        Exit Do 'If there is no folder to copy Exit Do
    Else
        For l As Integer = 0 To FolderList.Count - 1
            Dim fileSystemInfo As System.IO.FileSystemInfo

            Dim sourceDirectoryInfo As New System.IO.DirectoryInfo(FolderList(l))

            Dim dest As String = FolderList(l).Replace(dir_path, "")
            If (Not System.IO.Directory.Exists(des + "\" + dest)) Then 'create subFolder inside directory
                System.IO.Directory.CreateDirectory(des + "\" + dest)
            End If

            For Each fileSystemInfo In sourceDirectoryInfo.GetFileSystemInfos
                Dim destinationFileName As String = System.IO.Path.Combine(des + "\" + dest, fileSystemInfo.Name)
                If TypeOf fileSystemInfo Is System.IO.FileInfo Then
                    Dim streamRead As New System.IO.FileStream(fileSystemInfo.FullName, System.IO.FileMode.Open)
                    Dim streamWrite As New System.IO.FileStream(des + "\" + dest + "\" + fileSystemInfo.Name, IO.FileMode.Create, IO.FileAccess.Write, IO.FileShare.None)
                    Dim lngLen As Long = streamRead.Length - 1
                    newitm.SubItems(3).Text = "Copy bytes : (0/" + (lngLen * 100).ToString + ")"
                    Dim byteBuffer(1048576) As Byte   'our stream buffer
                    Dim intBytesRead As Integer    'number of bytes read
                    While streamRead.Position < lngLen    'keep streaming until EOF
                        newitm.SubItems(3).Text = "Copy bytes : (" + CInt(streamRead.Position).ToString + "/" + (lngLen * 100).ToString + ")"
                        intBytesRead = (streamRead.Read(byteBuffer, 0, 1048576))
                        streamWrite.Write(byteBuffer, 0, intBytesRead)
                        streamRead.Flush()
                    End While
                    'Clean up 
                    streamWrite.Flush()
                    streamWrite.Close()
                    streamRead.Close()

                    copied += 1
                    newitm.SubItems(4).Text = "Copied (" + copied.ToString + "/" + counter.ToString + ")"
                Else
                    FoldersInsideDirectory.Add(fileSystemInfo.FullName)
                End If
            Next
        Next
        FolderList.Clear()
        FolderList = FoldersInsideDirectory
    End If
    MsgBox("Done")
Loop

Answer 1

您需要指定FileShare.Read in the FileStream's constructor:

Read

Allows subsequent opening of the file for reading. If this flag is not specified, any request to open the file for reading (by this process or another process) will fail until the file is closed.

Dim streamRead As New System.IO.FileStream(fileSystemInfo.FullName, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read)

使用进度条将同一文件复制到多个位置/驱动器

Copying same file to multiple locations / drives with progress bar

vb.net

system.io.file