In this chapter, you learn how to read and write files, an essential aspect of many .NET applications. You touch on the major classes used to create, read from, and write to files, and the supporting classes used to manipulate the file system from C# code. Although you won't cover all of the classes in detail, this chapter will go into enough depth to give you a good idea of the concepts and fundamentals.
Files can be a great way to store data between instances of your application, or they can be used to transfer data between applications. User and application configuration settings can be stored to be retrieved the next time your application is run. Delimited text files, such as comma-separated files, are used by many legacy systems, and to interoperate with such systems you will need to know how to work with delimited data. As you will see, the .NET Framework provides you with the tools to use files effectively in your applications.
By the end of this chapter, you will have learned:
What a stream is and how .NET uses stream classes to access files
How to use the File object to manipulate the file structure
How to write to a file
How to read from a file
How to read and write formatted data from and to files
How to read and write compressed files
How to serialize and deserialize objects
How to monitor files and directories for changes