如何复制xlsx-File而不锁定它的Excel

我目前正在尝试编写一个方法来复制文件而不阻止其他应用程序更改它们。如果在阅读过程中有变化，我会再读一遍。

当我在记事本中更改文件时，它可以正常工作。但是当我试图在Excel 2010中保存文件时，我得到的消息是"{FileName}目前正在使用中。请稍后再试。"

我尝试使用。net Framework 3.5和。net Framework 4.0。

int partsToReadAtOnce = 5 * 1024 * 1024;
bool fileChangedDuringWrite = false;
using (FileStream readStr = new FileStream(srcPath, FileMode.Open, FileAccess.Read,FileShare.ReadWrite))
{
    using (FileStream writeStr = new FileStream(targetPath, FileMode.Create, FileAccess.Write,FileShare.None))
    {
        do
        {
            DateTime srcWriteTimeBefore = new FileInfo(srcPath).LastWriteTime;
            writeStr.SetLength(0);
            readStr.Seek(0, SeekOrigin.Begin);
            byte[] curData = new byte[partsToReadAtOnce];
            int len = 1;
            while ((len = readStr.Read(curData, 0, partsToReadAtOnce)) != 0)
            {
                writeStr.Write(curData, 0, len);
            }
            // break here and try to write to the file
            FileInfo srcInfo = new FileInfo(srcPath);
            FileInfo targetInfo = new FileInfo(targetPath);
            fileChangedDuringWrite = srcInfo.LastWriteTime.Ticks != srcWriteTimeBefore.Ticks
                || srcInfo.Length != targetInfo.Length;
        } while (fileChangedDuringWrite);
    }
}