Mono: A Developer's Notebook

Chapter 3. Core .NET

By now you’ve become familiar with the C# language, and you’ve seen some of its differences and similarities to Java and C/C++. We’ve alluded to some of the powerful Framework Class Library (FCL) classes, but we haven’t really gone into depth on them.

In this chapter, you’ll be introduced to the FCL and some of its most commonly used classes, including those that let you work with files, strings, regular expressions, collections, assemblies, process control, and threading. And, as a bonus, you’ll get your first look at NUnit, the .NET unit testing framework.

Work with Files

File I/O is an important part of any class library, and the FCL contains a complete and powerful set of file access classes. In this lab, you’ll see how to manipulate files and directories with Mono.

How do I do that?

You need to learn three basic classes in the FCL to manage files. They are File, TextReader, and TextWriter. Example 3-1 shows the source for a class that uses these three classes to create a file, write to it, read from it, and set some of the file’s attributes.

Note

Reading, writing, and `rithmetic may be elementary skills, but Mono makes them even easier.

Example 3-1. 01-files/FileCreator.cs

// 03-keyfunc/01-files using System; using System.IO; public class FileCreator { public static void Main(string [ ] args) { string file = args[0]; if (File.Exists(file)) { Console.WriteLine("File {0} exists with attributes {1}," + "created at {2}", file, File.GetAttributes(file), File.GetCreationTime(file)); ...