FileInfo fi = new FileInfo("C:\test.txt");
Console.WriteLine(fi.CreationTime.ToString());
Console.WriteLine(fi.LastWriteTime.ToString());
Console.WriteLine(fi.LastAccessTime.ToString());
// 改变(设置)文件的创建、修改、访问时间
File.SetCreationTime("C:\test.txt", DateTime.Now.AddYears(-1));
File.SetLastWriteTime("C:\test.txt", DateTime.Now.AddYears(-2));
File.SetLastAccessTime("C:\test.txt", DateTime.Now.AddYears(-3));