文件复制时，文件夹复制被拒绝

Question

        private void button3_Click(object sender, EventArgs e)
        {
            IEnumerable<string> fileNameList = Directory.EnumerateFileSystemEntries(sourcePath);
            foreach (var fileName in fileNameList)
            {
                FileInfo fileInfo = new FileInfo(fileName);
                File.Copy(fileName, targetPath + "\\"+ fileInfo.Name);
            }
        }

传入sourcePath以及targetPath，执行到File.Copy这步，如果sourcePath里都是文件，则正常执行复制。如含有文件夹，则迭代到文件夹的时候，报错System.UnauthorizedAccessException，路径sourcePath的访问被拒绝。请教是什么问题？

Answer 1

https://stackoverflow.com/que...

File.Copy(file, dest, true);
File.SetAttributes(dest, FileAttributes.Normal);