- •Microsoft C# Programming for the Absolute Beginner
- •Table of Contents
- •Microsoft C# Programming for the Absolute Beginner
- •Introduction
- •Overview
- •Chapter 1: Basic Input and Output: A Mini Adventure
- •Project: The Mini Adventure
- •Reviewing Basic C# Concepts
- •Namespaces
- •Classes
- •Methods
- •Statements
- •The Console Object
- •.NET Documentation
- •Getting into the Visual Studio .Net Environment
- •Examining the Default Code
- •Creating a Custom Namespace
- •Adding Summary Comments
- •Creating the Class
- •Moving from Code to a Program
- •Compiling Your Program
- •Looking for Bugs
- •Getting Input from the User
- •Creating a String Variable
- •Getting a Value with the Console.ReadLine() Method
- •Incorporating a Variable in Output
- •Combining String Values
- •Combining Strings with Concatenation
- •Adding a Tab Character
- •Using the Newline Sequence
- •Displaying a Backslash
- •Displaying Quotation Marks
- •Launching the Mini Adventure
- •Planning the Story
- •Creating the Variables
- •Getting Values from the User
- •Writing the Output
- •Finishing the Program
- •Summary
- •Chapter 2: Branching and Operators: The Math Game
- •The Math Game
- •Using Numeric Variables
- •The Simple Math Game
- •Numeric Variable Types
- •Integer Variables
- •Long Integers
- •Data Type Problems
- •Math Operators
- •Converting Variables
- •Explicit Casting
- •The Convert Object
- •Creating a Branch in Program Logic
- •The Hi Bill Game
- •Condition Testing
- •The If Statement
- •The Else Clause
- •Multiple Conditions
- •Working with The Switch Statement
- •The Switch Demo Program
- •Examining How Switch Statements Work
- •Creating a Random Number
- •Introducing the Die Roller
- •Exploring the Random Object
- •Creating a Random Double with the .NextDouble() Method
- •Getting the Values of Dice
- •Creating the Math Game
- •Designing the Game
- •Creating the Variables
- •Managing Addition
- •Managing Subtraction
- •Managing Multiplication and Division
- •Checking the Answers
- •Waiting for the Carriage Return
- •Summary
- •Chapter 3: Loops and Strings: The Pig Latin Program
- •Project: The Pig Latin Program
- •Investigating The String Object
- •The String Mangler Program
- •A Closer Look at Strings
- •Using the Object Browser
- •Experimenting with String Methods
- •Performing Common String Manipulations
- •Using a For Loop
- •Examining The Bean Counter Program
- •Creating a Sentry Variable
- •Checking for an Upper Limit
- •Incrementing the Variable
- •Examining the Behavior of the For Loop
- •The Fancy Beans Program
- •Skipping Numbers
- •Counting Backwards
- •Using a Foreach Loop to Break Up a Sentence
- •Using a While Loop
- •The Magic Word Program
- •Writing an Effective While Loop
- •Planning Your Program with the STAIR Process
- •S: State the Problem
- •T: Tool Identification
- •A: Algorithm
- •I: Implementation
- •R: Refinement
- •Applying STAIR to the Pig Latin Program
- •Stating the Problem
- •Identifying the Tools
- •Creating the Algorithm
- •Implementing and Refining
- •Writing the Pig Latin Program
- •Setting Up the Variables
- •Creating the Outside Loop
- •Dividing the Phrase into Words
- •Extracting the First Character
- •Checking for a Vowel
- •Adding Debugging Code
- •Closing Up the code
- •Summary
- •Introducing the Critter Program
- •Creating Methods to Reuse Code
- •The Song Program
- •Building the Main() Method
- •Creating a Simple Method
- •Adding a Parameter
- •Returning a Value
- •Creating a Menu
- •Creating a Main Loop
- •Creating the Sentry Variable
- •Calling a Method
- •Working with the Results
- •Writing the showMenu() Method
- •Getting Input from the User
- •Handling Exceptions
- •Returning a Value
- •Creating a New Object with the CritterName Program
- •Creating the Basic Critter
- •Using Scope Modifiers
- •Using a Public Instance Variable
- •Creating an Instance of the Critter
- •Adding a Method
- •Creating the talk() Method for the CritterTalk Program
- •Changing the Menu to Use the talk() Method
- •Creating a Property in the CritterProp Program
- •Examining the Critter Prop Program
- •Creating the Critter with a Name Property
- •Using Properties as Filters
- •Making the Critter More Lifelike
- •Adding More Private Variables
- •Adding the Age() Method
- •Adding the Eat() Method
- •Adding the Play() Method
- •Modifying the Talk() Method
- •Making Changes in the Main Class
- •Summary
- •Introducing the Snowball Fight
- •Inheritance and Encapsulation
- •Creating a Constructor
- •Adding a Constructor to the Critter Class
- •Creating the CritViewer Class
- •Reviewing the Static Keyword
- •Calling a Constructor from the Main() Method
- •Working with Multiple Files
- •Overloading Constructors
- •Viewing the Improved Critter Class
- •Adding Polymorphism to Your Objects
- •Modifying the Critter Viewer in CritOver to Demonstrate Overloaded Constructors
- •Using Inheritance to Make New Classes
- •Creating a Class to View the Clone
- •Creating the Critter Class
- •Improving an Existing Class
- •Introducing the Glitter Critter
- •Adding Methods to a New Class
- •Changing the Critter Viewer Again
- •Creating the Snowball Fight
- •Building the Fighter
- •Building the Robot Fighter
- •Creating the Main Menu Class
- •Summary
- •Overview
- •Introducing the Visual Critter
- •Thinking Like a GUI Programmer
- •Creating a Graphical User Interface (GUI)
- •Examining the Code of a Windows Program
- •Adding New Namespaces
- •Creating the Form Object
- •Creating a Destructor
- •Creating the Components
- •Setting Component Properties
- •Setting Up the Form
- •Writing the Main() Method
- •Creating an Interactive Program
- •Responding to a Simple Event
- •Creating and Adding the Components
- •Adding an Event to the Program
- •Creating an Event Handler
- •Allowing for Multiple Selections
- •Choosing a Font with Selection Controls
- •Creating the User Interface
- •Examining Selection Tools
- •Creating Instance Variables in the Font Chooser
- •Writing the AssignFont() Method
- •Writing the Event Handlers
- •Working with Images and Scroll Bars
- •Setting Up the Picture Box
- •Adding a Scroll Bar
- •Revisiting the Visual Critter
- •Designing the Program
- •Determining the Necessary Tools
- •Designing the Form
- •Writing the Code
- •Summary
- •Chapter 7: Timers and Animation: The Lunar Lander
- •Introducing the Lunar Lander
- •Reading Values from the Keyboard
- •Introducing the Key Reader Program
- •Setting Up the Key Reader Program
- •Coding the KeyPress Event
- •Coding the KeyDown Event
- •Determining Which Key Was Pressed
- •Animating Images
- •Introducing the ImageList Control
- •Setting Up an Image List
- •Looking at the Image Collection
- •Displaying an Image from the Image List
- •Using a Timer to Automate Animation
- •Introducing the Timer Control
- •Configuring the Timer
- •Adding Motion
- •Checking for Keyboard Input
- •Working with the Location Property
- •Detecting Collisions between Objects
- •Coding the Crasher Program
- •Getting Values for newX and newY
- •Bouncing the Ball off the Sides
- •Checking for Collisions
- •Extracting a Rectangle from a Component
- •Getting More from the MessageBox Object
- •Introducing the MsgDemo Program
- •Retrieving Values from the MessageBox
- •Coding the Lunar Lander
- •The Visual Design
- •The Constructor
- •The timer1_Tick() Method
- •The moveShip() Method
- •The checkLanding() Method
- •The theForm_KeyDown() Method
- •The showStats() Method
- •The killShip() Method
- •The initGame() Method
- •Summary
- •Chapter 8: Arrays: The Soccer Game
- •The Soccer Game
- •Introducing Arrays
- •Exploring the Counter Program
- •Creating an Array of Strings
- •Referring to Elements in an Array
- •Working with Arrays
- •Using the Array Demo Program to Explore Arrays
- •Building the Languages Array
- •Sorting the Array
- •Designing the Soccer Game
- •Solving a Subset of the Problem
- •Adding Percentages for the Other Players
- •Setting Up the Shot Demo Program
- •Setting Up the List Boxes
- •Using a Custom Event Handler
- •Writing the changeStatus() Method
- •Kicking the Ball
- •Designing Programs by Hand
- •Examining the Form by Hand Program
- •Adding Components in the Constructor
- •Responding to the Button Event
- •Building the Soccer Program
- •Setting Up the Variables
- •Examining the Constructor
- •Setting Up the Players
- •Setting Up the Opponents
- •Setting Up the Goalies
- •Responding to Player Clicks
- •Handling Good Shots
- •Handling Bad Shots
- •Setting a New Current Player
- •Handling the Passage of Time
- •Updating the Score
- •Summary
- •Chapter 9: File Handling: The Adventure Kit
- •Introducing the Adventure Kit
- •Viewing the Main Screen
- •Loading an Adventure
- •Playing an Adventure
- •Creating an Adventure
- •Reading and Writing Text Files
- •Exploring the File IO Program
- •Importing the IO Namespace
- •Writing to a Stream
- •Reading from a Stream
- •Creating Menus
- •Exploring the Menu Demo Program
- •Adding a MainMenu Object
- •Adding a Submenu
- •Setting Up the Properties of Menu Items
- •Writing Event Code for Menus
- •Using Dialog Boxes to Enhance Your Programs
- •Exploring the Dialog Demo Program
- •Adding Standard Dialogs to Your Form
- •Using the File Dialog Controls
- •Responding to File Dialog Events
- •Using the Font Dialog Control
- •Using the Color Dialog Control
- •Storing Entire Objects with Serialization
- •Exploring the Serialization Demo Program
- •Creating the Contact Class
- •Referencing the Serializable Namespace
- •Storing a Class
- •Retrieving a Class
- •Returning to the Adventure Kit Program
- •Examining the Room Class
- •Creating the Dungeon Class
- •Writing the Game Class
- •Writing the Editor Class
- •Writing the MainForm Class
- •Summary
- •Chapter 10: Chapter Basic XML: The Quiz Maker
- •Introducing the Quiz Maker Game
- •Taking a Quiz
- •Creating and Editing Quizzes
- •Investigating XML
- •Defining XML
- •Creating an XML Document in .NET
- •Creating an XML Schema for Your Language
- •Investigating the .NET View of XML
- •Exploring the XmlNode Class
- •Exploring the XmlDocument Class
- •Reading an Existing XML Document
- •Creating the XML Viewer Program
- •Writing New Values to an XML Document
- •Building the Document Structure
- •Adding an Element to the Document
- •Displaying the XML Code
- •Examining the Quizzer Program
- •Building the Main Form
- •Writing the Quiz Form
- •Writing the Editor Form
- •Summary
- •Overview
- •Introducing the SpyMaster Program
- •Creating a Simple Database
- •Accessing the Data Server
- •Accessing the Data in a Program
- •Using Queries to Modify Data Results
- •Limiting Data with the SELECT Statement
- •Using an Existing Database
- •Adding the Capability to Display Queries
- •Creating a Visual Query Builder
- •Working with Relational Databases
- •Improving Your Data with Normalization
- •Using a Join to Connect Two Tables
- •Creating a View
- •Referring to a View in a Program
- •Incorporating the Agent Specialty Attribute
- •Working with Other Databases
- •Creating a New Connection
- •Converting a Data Set to XML
- •Reading from XML to a Data Source
- •Creating the SpyMaster Database
- •Building the Main Form
- •Editing the Assignments
- •Editing the Specialties
- •Viewing the Agents
- •Editing the Agent Data
- •Summary
- •List of Figures
- •List of Tables
- •List of Sidebars
currently running is trapped inside an endless loop.
One way to remember these elements of the while loop is to think back to the for loop syntax. The for loop structure requires you to think about the characteristics of a well formed loop. You are required to define and initialize a sentry variable, define a condition, and ensure that the variable changes to a value that can trigger the end of the loop.
Planning Your Program with the STAIR Process
You are learning a lot of new syntax and many new strategies for thinking about information and programming. However, all these skills and syntax details are not the most important part of the programming process. You can always look up syntax or find a new command on the online help. The most challenging part of the programming process is the creative aspect. You have to be able to visualize a problem and apply a solution to that problem. You also need a framework for your solution so that you don’t find yourself staring at a blank screen, wondering what to do next. The next section helps you create that framework.
You don’t have to take a class in software engineering or project management to take advantage of good planning strategy for writing your program. I was part of a group of computer scientists at Indiana University which devised a strategy named STAIR to simplify the project−planning process. This strategy helps you avoid the headaches of program planning. STAIR is an acronym for a general problem−solving technique, but that technique is especially well suited for programming problems. STAIR stands for State the problem, Tool identification, Algorithm, Implementation, Refinement. I will explain each of these steps now.
S: State the Problem
The first thing you must do is write down the problem in clear, concise English (or whatever your primary language is). This sounds like the easiest step, but it’s the most difficult. Your statement of the problem should plainly indicate what you want to accomplish—a sentence or paragraph that describes what the program should do. You should avoid the temptation to get technical here. The actual technologies, commands, and syntax are completely irrelevant at this stage. Your grandmother should be able to read and understand your statement of the problem. (Well, if your grandmother happens to be a hotshot programmer, get somebody else to look at your problem statement!) Later in the process, you will become confused, and it will be helpful to have a record somewhere of what you are trying to accomplish. In C#, I like to include my statement of the problem in the actual code as part of the summary.
T: Tool Identification
After you gain a solid understanding of the problem you want to solve, it’s smart to make a list of the tools you will use to solve that problem. Tools can be many things. They can be various commands or objects in the C# language, techniques (such as the random number algorithm I show you in Chapter 2), or structures (such as a while loop). As you gain programming experience, you will learn more tools, and you’ll have more practice applying various tools to programming situations. In this book, the program that begins and ends each chapter is devised to illustrate the tools introduced in the chapter. I usually write the names of variables I will need and any major control structures I will use. The exact order and details of how the tools will be used can wait. Often, I list tools that I don’t end up using. Golfers usually leave the clubhouse with many clubs in their bags. They can’t usually
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take every club they own, so they select a set of clubs that are likely to be useful for the course they are playing. Identifying tools is a lot like that.
A: Algorithm
After you identify the possible tools, think about your programming strategy. Programmers call a specific programming strategy an algorithm. (Nice sound to it. You have seen by now that programmers love complicated names for simple things.) Now it’s time to think about the order in which you will do things. Some programmers use flowcharts or state diagrams to illustrate how the code is supposed to act. For small programs like those in this book, I usually use a simple list of instructions on paper. By the time you get to the algorithm step, you are actually writing down a form of shorthand to record the kinds of steps you will be taking.
Let me emphasize again that the algorithm should be written down. If you work all this out on paper before you turn on the computer, your programming efforts will be much less painful than if you simply sit down and start banging away.
In the Real World
As you begin to program, no doubt you will run into somebody who is an experienced programmer. Very often, that person will say something like “I never plan my algorithms.” Although many experienced programmers do not use written documentation for their simpler programs, ask them how long it took them to learn and how many mistakes they made when starting. At professional software development houses, programmers are often not allowed to start working on a program until the plan is developed. You don’t have to use STAIR, but if you do not use a scheme to plan your programs before you begin coding, you will run into big problems. If you don’t believe me, try writing programs without a plan and see what happens.
I: Implementation
You might be surprised that none of the first three steps require a computer. The best programming happens far from a computer. I wrote the core of one of my most useful programs on the back of an agenda at a very boring meeting. No computer was in sight, but all the real work could be done with paper and pencil. (Don’t tell my boss about this—he thought I was furiously taking notes about the meeting.)
The implementation stage begins when you turn on the computer and write code. When most people begin programming, they jump directly to this step. (Instead of the STAIR process, they must use the IR process.) If you can succeed by jumping right into the program without planning, that’s fine. Sooner or later, though, you’ll be totally clueless about how to proceed. That’s when you need to back up and think more carefully about the entire problem. Generally, the implementation phase is the easiest part of programming. If your algorithm is written correctly, translating it into working code is a simple matter. If I look at each line of an algorithm and can say, “I know how to do that,” the algorithm is ready for implementation.
Trick Keep your STAIR documentation around. You never know when it will come in handy. I once wrote a program named ABNIAC that simulates a simple machine language computer. I got a chance to demonstrate the program on television, but I had written the program in Visual Basic, which works only on the Windows operating system. The television studio used a Macintosh, so my program would
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