public async Task <IFile> CopyFromAsync(IFile file, string targetPath) { Guard.ArgumentNotNull(file, nameof(file)); if (!file.Exists) { throw new ArgumentException("要从中复制内容的源文件不存在。", nameof(file)); } Guard.ArgumentIsRelativePath(targetPath, nameof(targetPath)); string fullPath = _fileMapping.GetFilePath(targetPath, _scope); using (var fs = await file.CreateReadStreamAsync()) { return(await CreateFileAsync(fullPath, fs)); } }