C＃字节文件复制挂在filestream.close上

Question

我正在尝试使用c＃winforms应用中的进度条实现文件副本。 现在只需一个线程。 我发现文件传递达到100％并在filestream.close（）上挂起了很长时间。 目的地是UNC路径。

我的实施有什么问题？

// Create source and destination file streams
using (var inputFileStream = new FileStream(sourceFilePath, FileMode.Open, FileAccess.Read))
using (var outputFileStream = new FileStream(destPath + Path.GetFileNameWithoutExtension(sourceFilePath) + ".tfr", FileMode.Create))
{
    long sourceFileSize = inputFileStream.Length;
    int offset = 0;
    int bufferSize = 1024;
    var buffer = new byte[bufferSize];
    int progressPercent;

    while(offset < sourceFileSize)
    {
        // Fill buffer
        inputFileStream.Read(buffer, 0, bufferSize);

        // Empty buffer to output stream
        outputFileStream.Write(buffer, 0, bufferSize);

        // Flush buffer
        //Array.Clear(buffer, 0, buffer.Length);

        // Advance read offset
        offset += bufferSize;

        // Update GUI
        progressPercent = Convert.ToInt32(((double)offset / (double)sourceFileSize) * 100.0);
        pBar.Value = progressPercent;
        pBar.Refresh();
        labUploadStatus.Text = $"Uploading file...{progressPercent}%";
        labUploadStatus.Refresh();
    }

    outputFileStream.Close();
    inputFileStream.Close();
}