C# 12 in a Nutshell

Chapter 15. Streams and I/O

This chapter describes the fundamental types for input and output in .NET, with emphasis on the following topics:

• The .NET stream architecture and how it provides a consistent programming interface for reading and writing across a variety of I/O types

• Classes for manipulating files and directories on disk

• Specialized streams for compression, named pipes, and memory-mapped files

This chapter concentrates on the types in the System.IO namespace, the home of lower-level I/O functionality.

Stream Architecture

The .NET stream architecture centers on three concepts: backing stores, decorators, and adapters, as shown in Figure 15-1.

A backing store is the endpoint that makes input and output useful, such as a file or network connection. Precisely, it is either or both of the following:

• A source from which bytes can be sequentially read

• A destination to which bytes can be sequentially written

Figure 15-1. Stream architecture

A backing store is of no use, though, unless exposed to the programmer. A Stream is the standard .NET class for this purpose; it exposes a standard set of methods for reading, writing, and positioning. Unlike an array, for which all the backing data exists in memory at once, a stream deals with data serially—either one byte at a time or in blocks of a manageable size. Hence, a stream can use a small, fixed amount of memory regardless ...