Head First C#

Table of contents

1. Dedication
2. A Note Regarding Supplemental Files
3. Advance Praise for Head First C#
4. Praise for other Head First books
5.  
6. How to Use this Book: Intro
   1. Who is this book for?
   2. Who should probably back away from this book?
   3. We know what you’re thinking.
   4. And we know what your brain is thinking.
   5. Metacognition: thinking about thinking
   6. Here’s what WE did:
   7. Here’s what YOU can do to bend your brain into submission
   8. What you need for this book:
   9. Read me
   10. The technical review team
       1. Technical Reviewers:
   11. Acknowledgments
   12. Safari® Books Online
7. 1. Get Productive With c#: Visual Applications, in 10 minutes or less
   1. Why you should learn C#
      1. Here’s what the IDE automates for you...
      2. What you get with Visual Studio and C#...
   2. C# and the Visual Studio IDE make lots of things easy
   3. Help the CEO go paperless
   4. Get to know your users’ needs before you start building your program
   5. Here’s what you’re going to build
   6. What you do in Visual Studio...
   7. What Visual Studio does for you...
   8. Develop the user interface
   9. Visual Studio, behind the scenes
   10. Add to the auto-generated code
   11. You can already run your application
   12. Where are my files?
   13. Here’s what we’ve done so far
   14. We need a database to store our information
   15. The IDE created a database
   16. SQL is its own language
   17. Creating the table for the Contact List
   18. The blanks on contact card are columns in our People table
   19. Finish building the table
   20. Diagram your data
   21. Insert your card data into the database
   22. Connect your form to your database objects with a data source
   23. Add database-driven controls to your form
   24. Good programs are intuitive to use
   25. Test drive
       1. The IDE builds first, then runs.
   26. How to turn YOUR application into EVERYONE’S application
   27. Give your users the application
   28. You built a complete data-driven application
   29. You built a complete data-driven application
   30. CSharpcross
   31. CSharpcross Solution
8. 2. It’s All Just Code: Under the Hood
   1. When you’re doing this...
   2. ...the IDE does this
   3. Where programs come from
      1. Every program starts out as source code files
      2. The .NET Framework gives you the right tools for the job
      3. Build the program to create an executable
      4. Your program runs inside the CLR
   4. The IDE helps you code
   5. When you change things in the IDE, you’re also changing your code
      1. Wait, wait! What did that say?
   6. Anatomy of a program
      1. Let’s take a closer look at your code
   7. Your program knows where to start
   8. You can change your program’s entry point
      1. So what happened?
   9. Two classes can be in the same namespace
   10. Your programs use variables to work with data
       1. Declare your variables
       2. Variables vary
       3. You have to assign values to variables before you use them
       4. A few useful types
   11. C# uses familiar math symbols
   12. Loops perform an action over and over again
       1. Use a code snippet to write simple for loops
   13. Time to start coding
       1. Add statements to show a message
   14. if/else statements make decisions
   15. Set up conditions and see if they’re true
       1. Use logical operators to check conditions
       2. Set a variable and then check its value
       3. Add another conditional test
       4. Add loops to your program
   16. Csharpcross
   17. Csharpcross Solution
9. 3. Objects: Get Oriented!: Making Code Make Sense
   1. How Mike thinks about his problems
   2. How Mike’s car navigation system thinks about his problems
   3. Mike’s Navigator class has methods to set and modify routes
      1. Some methods have a return value
   4. Use what you’ve learned to build a simple application
   5. Mike gets an idea
      1. He could create three different Navigator classes...
   6. Mike can use objects to solve his problem
   7. You use a class to build an object
      1. An object gets its methods from its class
   8. When you create a new object from a class, it’s called an instance of that class.
   9. A better solution... brought to you by objects!
   10. An instance uses fields to keep track of things
       1. Methods are what an object does. Fields are what the object knows.
   11. Let’s create some instances!
   12. Thanks for the memory
   13. What’s on your program’s mind
   14. You can use class and method names to make your code intuitive
   15. Give your classes a natural structure
       1. Let’s build a class diagram
   16. Class diagrams help you organize your classes so they make sense
   17. Build a class to work with some guys
   18. Create a project for your guys
   19. Build a form to interact with the guys
   20. There’s an even easier way to initialize objects
   21. A few ideas for designing intuitive classes
   22. Objectcross
   23. Objectcross Solution
10. 4. Types and References: It’s 10:00. Do you know where your data is?
    1. The variable’s type determines what kind of data it can store
    2. A variable is like a data to-go cup
    3. 10 pounds of data in a 5 pound bag
    4. Even when a number is the right size, you can’t just assign it to any variable
       1. So what happened?
    5. When you cast a value that’s too big, C# will adjust it automatically
    6. C# does some casting automatically
    7. When you call a method, the variables must match the types of the parameters
    8. Combining = with an operator
    9. Objects use variables, too
    10. Refer to your objects with reference variables
    11. References are like labels for your object
    12. If there aren’t any more references, your object gets garbage collected
    13. Typecross
    14. Multiple references and their side effects
    15. Two references means TWO ways to change an object’s data
    16. A special case: arrays
        1. Use each element in an array like it is a normal variable
    17. Arrays can contain a bunch of reference variables, too
    18. Welcome to Sloppy Joe’s Budget House o’ Discount Sandwiches!
    19. Objects use references to talk to each other
    20. Where no object has gone before
    21. Typecross Solution
11. I. C# Lab A Day at the Races
    1. 5. Encapsulation: Keep your privates... private
       1. Kathleen is an event planner
       2. What does the estimator do?
       3. Kathleen’s Test Drive
       4. Each option should be calculated individually
       5. It’s easy to accidentally misuse your objects
       6. Encapsulation means keeping some of the data in a class private
       7. Use encapsulation to control access to your class’s methods and fields
       8. But is the realName field REALLY protected?
       9. Private fields and methods can only be accessed from inside the class
       10. A few ideas for encapsulating classes
       11. Encapsulation keeps your data pristine
           1. A quick example of encapsulation
       12. Properties make encapsulation easier
       13. Build an application to test the Farmer class
       14. Use automatic properties to finish the class
           1. Fully encapsulate the Farmer class
       15. What if we want to change the feed multiplier?
       16. Use a constructor to initialize private fields
    2. 6. Inheritance: Your object’s family tree
       1. Kathleen does birthday parties, too
       2. We need a BirthdayParty class
          1. Here’s what we need to do:
       3. One more thing... can you add a $100 fee for parties over 12?
       4. When your classes use inheritance, you only need to write your code once
          1. Dinner parties and birthday parties are both parties
       5. Build up your class model by starting general and getting more specific
       6. How would you design a zoo simulator?
       7. Use inheritance to avoid duplicate code in subclasses
       8. Different animals make different noises
          1. Think about what you need to override
       9. Think about how to group the animals
       10. Create the class hierarchy
       11. Every subclass extends its base class
           1. C# always calls the most specific method
       12. Use a colon to inherit from a base class
       13. We know that inheritance adds the base class fields, properties, and methods to the subclass...
           1. ... but some birds don’t fly!
       14. A subclass can override methods to change or replace methods it inherited
       15. Any place where you can use a base class, you can use one of its subclasses instead
       16. A subclass can access its base class using the base keyword
       17. When a base class has a constructor, your subclass needs one too
           1. The base class constructor is executed before the subclass constructor
       18. Now you’re ready to finish the job for Kathleen!
       19. Build a beehive management system
       20. First you’ll build the basic system
       21. Use inheritance to extend the bee management system
    3. 7. Interfaces and Abstract Classes: Making classes keep their promises
       1. Let’s get back to bee-sics
          1. Lots of things are still the same
       2. We can use inheritance to create classes for different types of bees
       3. An interface tells a class that it must implement certain methods and properties
       4. Use the interface keyword to define an interface
       5. Now you can create an instance of NectarStinger that does both jobs
       6. Classes that implement interfaces have to include ALL of the interface’s methods
       7. Get a little practice using interfaces
       8. You can’t instantiate an interface, but you can reference an interface
       9. Interface references work just like object references
       10. You can find out if a class implements a certain interface with “is”
       11. Interfaces can inherit from other interfaces
           1. Any class that implements an interface that inherits from IWorker must implement its methods and properties
       12. The RoboBee 4000 can do a worker bee’s job without using valuable honey
       13. is tells you what an object implements, as tells the compiler how to treat your object
       14. A CoffeeMaker is also an Appliance
       15. Upcasting works with both objects and interfaces
       16. Downcasting lets you turn your appliance back into a coffee maker
           1. When downcasting fails, as returns null
       17. Upcasting and downcasting work with interfaces, too
       18. There’s more than just public and private
       19. Access modifiers change scope
       20. Some classes should never be instantiated
       21. An abstract class is like a cross between a class and an interface
       22. Like we said, some classes should never be instantiated
           1. Solution: use an abstract class
       23. An abstract method doesn’t have a body
           1. Avoid ambiguity!
           2. The four princples of object oriented programming
       24. Polymorphism means that one object can take many different forms
           1. Keep your eyes open for polymorphism in the next exercise!
           2. But we’re not done yet!
    4. 8. Enums and Collections: Storing lots of data
       1. Strings don’t always work for storing categories of data
       2. Enums let you enumerate a set of valid values
       3. Enums let you represent numbers with names
       4. We could use an array to create a deck of cards...
          1. ... but what if you wanted to do more?
       5. Arrays are hard to work with
       6. Lists make it easy to store collections of... anything
       7. Lists are more flexible than arrays
       8. Lists shrink and grow dynamically
       9. List objects can store any type
       10. Collection initializers work just like object initializers
       11. Let’s create a list of Ducks
           1. Here’s the initializer
       12. Lists are easy, but SORTING can be tricky
           1. You could sort a list of ducks by size...
           2. ...or by type.
           3. Lists know how to sort themselves
       13. Two ways to sort your ducks
           1. An object’s CompareTo() method compares it with another object
       14. Use IComparer to tell your List how to sort
       15. Create an instance of your comparer object
           1. Multiple IComparer implementations, multiple ways to sort your objects
       16. IComparer can do complex comparisons
       17. Use a dictionary to store keys and values
       18. The Dictionary Functionality Rundown
       19. Your key and value can be different types, too
       20. You can build your own overloaded methods
       21. And yet MORE collection types...
           1. Generic collections are an important part of the .NET framework
       22. A queue is FIFO — First In, First Out
       23. A stack is LIFO — Last In, First Out
12. II. C# Lab: The Quest
    1. 9. Reading and Writing Files: Save the byte array, save the world
       1. C# uses streams to read and write data
       2. Different streams read and write different things
          1. Things you can do with a stream:
       3. A FileStream writes bytes to a file
       4. How to write text to a file in 3 simple steps
       5. The Swindler launches another diabolical plan
       6. Reading and writing takes two objects
       7. Data can go through more than one stream
       8. Use built-in objects to pop up standard dialog boxes
          1. ShowDialog() pops up a dialog box
       9. Dialog boxes are just another .NET control
       10. Dialog boxes are objects, too
       11. Use the built-in File and Directory classes to work with files and directories
           1. Things you can do with a File:
           2. Things you can do with a Directory:
       12. Use File Dialogs to open and save files (all with just a few lines of code)
       13. IDisposable makes sure your objects are disposed properly
       14. Avoid file system errors with using statements
           1. Use multiple using statements for multiple objects
       15. Trouble at work
           1. You can help Brian out by building a program to manage his excuses
       16. Writing files usually involves making a lot of decisions
       17. Use a switch statement to choose the right option
       18. Use a switch statement to let your deck of cards read from a file or write itself out to one
       19. Add an overloaded Deck() constructor that reads a deck of cards in from a file
       20. What happens to an object when it’s serialized?
       21. But what exactly IS an object’s state? What needs to be saved?
       22. When an object is serialized, all of the objects it refers to get serialized too...
       23. Serialization lets you read or write a whole object all at once
           1. You’ll need a BinaryFormatter object
           2. Now just create a stream and read or write your objects
       24. If you want your class to be serializable, mark it with the [Serializable] attribute
       25. Let’s serialize and deserialize a deck of cards
       26. .NET converts text to Unicode automatically
       27. C# can use byte arrays to move data around
       28. Use a BinaryWriter to write binary data
           1. Use BinaryReader to read the data back in
       29. You can read and write serialized files manually, too
       30. Find where the files differ, and use that information to alter them
       31. Working with binary files can be tricky
       32. Use file streams to build a hex dumper
           1. How to make a hex dump
           2. Working with hex
       33. StreamReader and StreamWriter will do just fine
    2. 10. Exception Handling: Putting out fires gets old
       1. Brian needs his excuses to be mobile
          1. But the program isn’t working!
       2. When your program throws an exception, .NET generates an Exception object.
       3. Brian’s code did something unexpected
       4. All exception objects inherit from Exception
       5. The debugger helps you track down and prevent exceptions in your code
          1. Debugging means running your code line by line to see what happens
       6. Use the IDE’s debugger to ferret out exactly what went wrong in the excuse manager
       7. Uh-oh—the code’s still got problems...
       8. Handle exceptions with try and catch
       9. What happens when a method you want to call is risky?
       10. Use the debugger to follow the try/catch flow
       11. If you have code that ALWAYS should run, use a finally block
       12. Use the Exception object to get information about the problem
       13. Use more than one catch block to handle multiple types of exceptions
       14. One class throws an exception, another class catches the exception
       15. Bees need an OutOfHoney exception
       16. An easy way to avoid a lot of problems: using gives you try and finally for free
       17. Exception avoidance: implement IDisposable to do your own clean up
       18. The worst catch block EVER: comments
           1. You should handle your exceptions, not bury them
       19. Temporary solutions are okay (temporarily)
       20. A few simple ideas for exception handling
       21. Brian finally gets his vacation...
           1. ... and things are looking up back home!
    3. 11. Events and Delegates: What your code does when you’re not looking
       1. Ever wish your objects could think for themselves?
       2. But how does an object KNOW to respond?
       3. When an EVENT occurs... objects listen
          1. Want to DO SOMETHING with an event? You need an event handler
       4. One object raises its event, others listen for it...
       5. Then, the other objects handle the event
       6. Connecting the dots
          1. Use a standard name when you add a method to raise an event
       7. The IDE creates event handlers for you automatically
       8. The forms you’ve been building all use events
          1. One event, multiple handlers
       9. Connecting event senders with event receivers
          1. “My people will get in touch with your people.”
       10. A delegate STANDS IN for an actual method
           1. A delegate adds a new type to your project
       11. Delegates in action
       12. Any object can subscribe to a public event...
           1. ... but that’s not always a good thing!
       13. Use a callback instead of an event to hook up exactly one object to a delegate
       14. Callbacks use delegates, but NOT events
    4. 12. Review and Preview: Knowledge, power, and building cool stuff
       1. You’ve come a long way, baby
       2. We’ve also become beekeepers
          1. But we can do a lot better now...
       3. The beehive simulator architecture
       4. Building the beehive simulator
       5. Life and death of a flower
       6. Now we need a Bee class
       7. P. A. H. B. (Programmers Against Homeless Bees)
       8. The hive runs on honey
       9. Filling out the Hive class
       10. The hive’s Go() method
       11. We’re ready for the World
           1. The World object keeps everything Go() ing
       12. We’re building a turn-based system
       13. Here’s the code for World
       14. Giving the bees behavior
       15. The main form tells the world to Go()
       16. We can use World to get statistics
       17. Timers fire events over and over again
       18. The timer’s using a delegate behind the scenes
       19. Add a Timer to the simulator
       20. Test drive
       21. Let’s work with groups of bees
       22. A collection collects... DATA
       23. LINQ makes working with data in collections and databases easy
       24. Test drive (Part 2)
       25. One final challenge: Open and Save
    5. 13. Controls and Graphics: Make it pretty
       1. You’ve been using controls all along to interact with your programs
       2. Form controls are just objects
       3. Use controls to animate the beehive simulator
       4. Add a renderer to your architecture
       5. The renderer draws everything in the World on the two forms
          1. The simulator renders the world after each frame
       6. Controls are well-suited for visual display elements
       7. Build your first animated control
          1. We want a control in the toolbox
       8. BeeControl is LIKE a PictureBox... so let’s start by INHERITING from PictureBox
       9. Create a button to add the BeeControl to your form
       10. Your controls need to dispose their controls, too!
       11. A UserControl is an easy way to build a control
       12. The renderer uses your BeeControl to draw animated bees on your forms
       13. Add the hive and field forms to the project
           1. Figure out where your locations are
       14. Build the Renderer
       15. Now connect the main form to your two new forms, HiveForm and FieldForm
       16. Test drive... ahem... buzz
       17. Looks great, but something’s not quite right...
       18. Let’s take a closer look at those performance issues
       19. You resized your Bitmaps using a Graphics object
           1. Let’s see image resizing in action
       20. Your image resources are stored in Bitmap objects
           1. Then each Bitmap is drawn to the screen
           2. The bigger they are...
       21. Use System.Drawing to TAKE CONTROL of graphics yourself
       22. A 30-second tour of GDI+ graphics
       23. Use graphics to draw a picture on a form
       24. Graphics can fix our transparency problem...
           1. ... but there’s a catch
       25. Use the Paint event to make your graphics stick
       26. A closer look at how forms and controls repaint themselves
       27. Double buffering makes animation look a lot smoother
       28. Double buffering is built into forms and controls
           1. Overhaul the Beehive Simulator
       29. Use a Graphics object and an event handler for printing
       30. PrintDocument works with the print dialog and print preview window objects
           1. Use e.HasMorePages to print multi-page documents
       31. There’s so much more to be done...
    6. 14. Captain Amazing the Death of the Object
       1. Your last chance to DO something... your object’s finalizer
       2. When EXACTLY does a finalizer run?
          1. You can SUGGEST to .NET that it’s time to collect the garbage
       3. Dispose() works with using, finalizers work with garbage collection
       4. Finalizers can’t depend on stability
       5. Make an object serialize itself in its Dispose()
       6. A struct looks like an object...
       7. ..but isn’t on the heap
       8. Values get copied, references get assigned
       9. Structs are value types; objects are reference types
          1. Here’s what happened...
       10. The stack vs. the heap: more on memory
       11. Captain Amazing... not so much
       12. Extension methods add new behavior to EXISTING classes
       13. Extending a fundamental type: string
    7. 15. Linq: Get control of your data
       1. An easy project...
       2. ... but the data’s all over the place
       3. LINQ can pull data from multiple sources
       4. .NET collections are already set up for LINQ
       5. LINQ makes queries easy
       6. LINQ is simple, but your queries don’t have to be
       7. LINQ is versatile
       8. LINQ can combine your results into groups
       9. Combine Jimmy’s values into groups
       10. Use join to combine two collections into one query
       11. Jimmy saved a bunch of dough
       12. Connect LINQ to a SQL database
       13. Use a join query to connect Starbuzz and Objectville
13. III. C# Lab 3: Invaders
    1. A. Leftovers: The top 5 things we wanted to include in this book
       1. #1 LINQ to XML
          1. Save and load XML files
          2. Query your data
          3. Read data from an RSS feed
       2. #2 Refactoring
          1. Extract a method
          2. Rename a variable
          3. Consolidate a conditional expression
       3. #3 Some of our favorite Toolbox components
       4. #4 Console Applications
       5. #5 Windows Presentation Foundation
       6. Did you know that C# and the .NET Framework can...
14. Index
15. About the Authors
16. Copyright