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目前我正在 vb.net 中做项目，我想在将文件从一个文件夹复制到另一个文件夹时设置进度条。并且进度条应根据复制的文件量向完成移动。

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2 回答 2

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不是那么新的问题，但这里有一个答案。以下代码将达到预期的结果，从而跟踪单个文件的进度。它使用 1 MiB 缓冲区。根据您的系统资源，您可以相应地调整缓冲区以调整传输性能。

概念：在读取/写入每个字节时对其进行计数，并使用文件流根据源文件的总大小报告进度。

'Create the file stream for the source file
Dim streamRead as New System.IO.FileStream([sourceFile], System.IO.FileMode.Open)
'Create the file stream for the destination file
Dim streamWrite as New System.IO.FileStream([targetFile], System.IO.FileMode.Create)
'Determine the size in bytes of the source file (-1 as our position starts at 0)
Dim lngLen as Long = streamRead.Length - 1
Dim byteBuffer(1048576) as Byte   'our stream buffer
Dim intBytesRead as Integer    'number of bytes read

While streamRead.Position < lngLen    'keep streaming until EOF
    'Read from the Source
    intBytesRead = (streamRead.Read(byteBuffer, 0, 1048576))
    'Write to the Target
    streamWrite.Write(byteBuffer, 0, intBytesRead)
    'Display the progress
    ProgressBar1.Value = CInt(streamRead.Position / lngLen * 100)
    Application.DoEvents()    'do it
End While

'Clean up 
streamWrite.Flush()
streamWrite.Close()
streamRead.Close()
于 2016-01-22T04:50:51.680 回答
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使用的概念：在 中获取count of files，source directory然后每当copyingafile从source folder增加destination folderavariable以跟踪转移了多少files。现在files使用以下公式计算转移百分比，

% of files transferred = How many files Transferred * 100 / Total No of files in source folder

然后在获得 之后% of files transferred，使用它来更新进度条的值。

试试这个代码：Tested with IDE

  Dim xNewLocataion = "E:\Test1"

        Dim xFilesCount = Directory.GetFiles("E:\Test").Length
        Dim xFilesTransferred As Integer = 0

        For Each xFiles In Directory.GetFiles("E:\Test")

            File.Copy(xFiles, xNewLocataion & "\" & Path.GetFileName(xFiles), True)
            xFilesTransferred += 1

            ProgressBar1.Value = xFilesTransferred * 100 / xFilesCount
            ProgressBar1.Update()

        Next
于 2013-03-28T07:10:05.607 回答