Ch2, lesson2 - Reading & Writing Files.

• All stream classes derive from abstract class Stream.
• File class - static mthds for opening (r/w) & creating files.
• File class - can return FileStream obj or StreamReader, StreamWriter.
• FileStream - basic func for opening file streams for reading & writing.
• StreamReader/StreamWriter - easier. Reads stream as string.
• File - Open(), OpenText(), Create(), CreateText(). ...Text() ret StreamReader.
• StringReader/Writer - read to-fro in-memory strings.
• BinaryReader/Writer - handle binary data to/fro streams.
• MemoryStream - to create in-memory streams. Used where need to create a stream before really need to store it.
• MemoryStream - can wrap MemoryStream obj in StreamWriter to write to MemoryStream.