Question

我正在尝试使用FileStream将文件从目录复制到另一个目录并且工作正常，但在复制大文件时会抛出错误Arithmetic operation resulted in an overflow.它无法复制大于20MB的文件。请问我是编程新手，你可以帮助我吗？

Private mCurrentFile As String = String.Empty

Public ReadOnly Property CurrentFile() As String
    Get
        Return mCurrentFile
    End Get
End Property

Dim FS As FileStream
    mCurrentFile = GetFileName(URL)
    Dim wRemote As WebRequest
    Dim bBuffer As Byte()
    ReDim bBuffer(256)
    Dim iBytesRead As Integer
    Dim iTotalBytesRead As Integer

    FS = New FileStream(Location, FileMode.Create, FileAccess.Write)
    wRemote = WebRequest.Create(URL)
    Dim myWebResponse As WebResponse = wRemote.GetResponse
    RaiseEvent FileDownloadSizeObtained(myWebResponse.ContentLength)
    Dim sChunks As Stream = myWebResponse.GetResponseStream
    Do
        iBytesRead = sChunks.Read(bBuffer, 0, 256)

        FS.Write(bBuffer, 0, iBytesRead)
        iTotalBytesRead += iBytesRead
        If myWebResponse.ContentLength < iTotalBytesRead Then
            RaiseEvent AmountDownloadedChanged(myWebResponse.ContentLength)
        Else
            RaiseEvent AmountDownloadedChanged(iTotalBytesRead)
        End If
    Loop While Not iBytesRead = 0 And dStop = False
    sChunks.Close()
    FS.Close()

Private Sub _Downloader_FileDownloadSizeObtained(ByVal iFileSize As Long) Handles _Downloader.FileDownloadSizeObtained
    'FIRES WHEN WE HAVE GOTTEN THE DOWNLOAD SIZE, SO WE KNOW WHAT BOUNDS TO GIVE THE PROGRESS BAR
    ProgressBar1.Value = 0
    ProgressBar1.Maximum = CInt(iFileSize)
End Sub

错误抛出此处。

Private Sub _Downloader_AmountDownloadedChanged(ByVal iNewProgress As Long) Handles _Downloader.AmountDownloadedChanged
    'FIRES WHEN MORE OF THE FILE HAS BEEN DOWNLOADED
    ProgressBar1.Value = Convert.ToInt64(iNewProgress)  '<-------------- Error throws here
    Application.DoEvents()
End Sub

我不知道任何更大的类型可以处理大文件还是有其他方式？

VB.NET算术运算导致使用FileStream溢出

0 个答案: