Neal Stublen

Class Objectives  Develop an understanding of the.NET Framework  Gain proficiency using Visual Studio  Begin learning the C# programming language  Apply object-oriented concepts within the C# language  Develop basic Windows Forms applications  Learn basic.NET database concepts

Suggestions  Install Visual Studio Visual Studio Express 2013 for Windows Desktop  Review each chapter We won’t necessarily hit every point in class Bring back questions  Work projects at end of each chapter Make changes and experiment

Tonight’s Agenda  Overview of.NET  Using Visual Studio  Designing a Form  Object-Oriented Programming  Walk through a simple object example  Apply what we’ve learned  Q&A

Windows Applications Microsoft Windows OS / Intel Platform Windows Application File SystemNetworkDisplay

.NET Applications.NET Framework Class Libraries Common Language Runtime (CLR).NET Application (or "Assembly") Non-Microsoft OS? / Non-Intel Platform? Microsoft Windows OS / Intel Platform File SystemNetworkDisplay

C#,.NET, and Windows C# Source Files.NET "Assembly" (MSIL) C# Compiler.NET "Assembly" (MSIL) CLR "Native" Code

How does C# compare?  VB.NET, F#, Managed VC++ are other.NET languages They all compile into MSIL assemblies that run on the.NET CLR They all have their own unique syntax  Java has many similarities.NET class library instead of the Java support classes  Might be considered a "safer" version of C++.

Using Visual Studio  Start Visual Studio  Create a project Windows Forms for desktop applications Web Forms for web-based applications Console applications for the command line  The project represents all or part of an application  A solution is a container for multiple projects

Express Editions  Free Visual Studio versions us/products/visual-studio-express-vs.aspx us/products/visual-studio-express-vs.aspx

Visual Studio Summary  Project A collection of files that are used to generate an application or class library.csproj file extention  Solution A collection of projects.sln file extension  Open/close a project/solution  Projects target a specific version of the.NET Framework

Visual Studio Summary  Menus and toolbars can be customized  Solution Explorer manages project files  Form Designer allows us to create and modify forms  Controls are added to a form using the Toolbox  Properties change the appearance and/or function of a form or control

Visual Studio Summary  Tabbed windows can be docked just about anywhere  Tabbed windows can be floating or docked  Tabbed windows can be pinned or hidden  Code Editor allows you to edit source code  Editing window can be split into two panes

Visual Studio Summary  Settings can be imported and exported  We will work with WinForms applications in this class  Projects can be “built” and “run” from within Visual Studio

Form Design  Add controls from the toolbox  Set control properties Name, Text Enabled, ReadOnly, TabOrder, TabStop, TextAlign AcceptButton, CancelButton, StartPosition  Specify access keys (&)  Specify tab order between controls  Document Outline View  Renaming and saving files

Form Exercise  Create a project named "InvoiceTotal" in your S: folder  Reproduce the following form:  Consider tab order, access keys, etc.

Form Design Summary  Control Toolbox  Tab Order  Properties Window Name, Text Enabled, ReadOnly, TabOrder, TabStop, TextAlign AcceptButton, CancelButton, StartPosition  Access keys (&)  Document Outline View  Renaming and saving files

Object-Oriented Programming .NET represents everything as an "object"  What objects can we identify in our InvoiceTotal application? Forms, Controls

Object-Oriented Programming  Objects are made up of data and a set of functions that act on that data  What data would be stored in the InvoiceTotal form and its controls? Position, Text  What functions might use that data?

Objects and Classes  An object is represented by a "class"  A class has “member” data Variables  A class has “member” functions Methods

A class Definition class Counter { };

A class Definition class Counter { // “class” is a keyword that tells the // compiler we are defining a new type of // object. };

The class Name (or Type) class Counter { // “Counter” is the name of the new class // type. };

Member Variables class Counter { private int mValue; // We declare member variables that will // hold data for the class. };

Member Visibility class Counter { private int mValue; // “private” is a keyword that tells the // compiler the class member is not visible // to other objects. };

Member Type class Counter { private int mValue; // “int” is a built-in type that tells the // compiler we are defining an integer // value. };

Member Name class Counter { private int mValue; // “mValue” is the name we will use when // referring to this data member. };

Member Initializer class Counter { private int mValue = 0; // (Optional) We can assign an initial value to // the data member. };

A class Constructor class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } };

Constructor Visibility class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // “public” is a keyword that tells the // compiler the class member is visible to // other objects. };

Constructor Name class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // “Counter” repeats the class name, which // tells the compiler we are defining a // constructor for the class. };

Constructor Parameter class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // “int inInitialValue” is a parameter of // the constructor. It is used to set the // initial state of the object. };

Constructor Body class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // The body of the constructor assigns // initial values to any data members of // the class. };

Assignment Operator class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // “=” is an assignment operator that assigns // a value to a variable. };

A class Method class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // Increment the counter by one. public int Increment() { return ++mValue; } };

Method Visibility class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // Increment the counter by one. public int Increment() { return ++mValue; } };

Method Return Type class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // Increment the counter by one. public int Increment() { return ++mValue; } };

Method Name class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // Increment the counter by one. public int Increment() { return ++mValue; } };

Method Body class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // Increment the counter by one. public int Increment() { return ++mValue; } };

Prefix/Postfix Operators class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // Increment the counter by one. public int Increment() { return ++mValue; } };

Code Comments class Counter { private int mValue; // Constructor public Counter(int inInitialValue) { mValue = inInitialValue; } // Increment the counter by one. public void Increment() { mValue = mValue + 1; } }; Counter myCounter = new Counter(0);

Instantiating a class class Counter {... }; Counter myCounter = new Counter(0); Counter yourCounter = new Counter(10);

Instantiating a class class Counter {... }; Counter myCounter = new Counter(0); Counter yourCounter = new Counter(10); // “new” is a keyword that tells the compiler // we want to create an instance of the class. // We have created two instances of the Counter // class.

Instantiating a class class Counter {... }; Counter myCounter = new Counter(0); myCounter.Increment(); // We call a method by using the “.” operator on // a class instance. // All statements are terminated by a semi-colon.

What’s in a form?  A form is defined by a class  Controls on the form are member variables  Event handlers are member functions

Form Summary  The Code Editor allows us to expand and collapse blocks of code.  Forms are just objects  Forms are created by making changes to the object’s properties and calling the object’s methods.  The Designer just adds code to the form’s class.

Style Tips  Use of braces, parentheses, etc.  Use of indentation and spacing  Improves readability  Use code comments  Improves maintainability

Controls and Events  We can perform actions in response to Click events  Control events are handled by form methods

Event Summary  Forms and controls dispatch events  Event handlers respond to events

Best Practices  The calculator logic should not be part of the form  Place the calculator logic in a class that can be tested and used from many places

InvoiceCalculator  What methods would you place on an InvoiceCalculator object?  What data members would be part of the InvoiceCalculator object?  Refactoring the calculator