如何在添加wwwroot文件夹后重命名文件上传名并保留旧名称

public async Task<IActionResult> UploadFile(IFormFile file)
{
    if (file == null || file.Length == 0)
        return Content("文件为空，请选择一个文件上传。");

    var originalFilename = ContentDispositionHeaderValue.Parse(file.ContentDisposition).FileName.Trim('"');
    var fileExt = Path.GetExtension(originalFilename);
    var newFilename = Guid.NewGuid().ToString() + fileExt; // 使用GUID生成新文件名

    var path = Path.Combine(_hostingEnvironment.WebRootPath, "uploads", newFilename);

    using (var stream = new FileStream(path, FileMode.Create))
    {
        await file.CopyToAsync(stream);
    }

    // 保存原始文件名和新文件名的映射关系，例如存入数据库
    _context.FileNames.Add(new FileNameMapping { OriginalName = originalFilename, NewName = newFilename });
    await _context.SaveChangesAsync();

    return RedirectToAction(nameof(Index));
}