C# 2010 All-in-One For Dummies®

Chapter 3. Fishing the FileStream

In This Chapter

• Reading and writing data files

• Using the Stream classes

• Using the using statement

• Dealing with input/output errors

I once caught two trout on a single hook, in a lovely mountain stream in my native Colorado — quite a thrill for an 11-year-old. Fishing the "file stream" with C# isn't quite so thrilling, but it's one of those indispensable programming skills.

File access refers to the storage and retrieval of data on the disk. I cover basic text-file input/output in this chapter. Reading and writing data from databases is covered in Chapter 2 of this minibook, and reading and writing information to the Internet is covered in Chapter 4.

Going Where the Fish Are: The File Stream

The console application programs in this book mostly take their input from, and send their output to, the console. Programs outside this chapter have better — or at least different — things to bore you with than file manipulation. I don't want to confuse their message with the extra baggage of involved input/output (I/O). However, console applications that don't perform file I/O are about as common as Sierra Club banners at a paper mill.

The I/O classes are defined in the System.IO namespace. The basic file I/O class is FileStream. In days past, the programmer would open a file. The open command would prepare the file and return a handle. Usually, this handle was nothing more than a number, like the one they give you when you place an order at a Burger Whop. Every time ...