Mike McGrath C# Programming In easy steps is an imprint of In Easy Steps Limited 16 Hamilton Terrace . Holly Walk . Leamington Spa Warwickshire . CV32 4LY www.ineasysteps.com Copyright © 2016 by In Easy Steps Limited. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without prior written permission from the publisher. Notice of Liability Every effort has been made to ensure that this book contains accurate and current information. However, In Easy Steps Limited and the author shall not be liable for any loss or damage suffered by readers as a result of any information contained herein. Trademarks All trademarks are acknowledged as belonging to their respective companies. Contents 1 Getting started Introducing C# Installing Visual Studio Exploring the IDE Starting a Console project Writing your first program Following the rules Summary 2 Storing values Creating variables Reading input Employing arrays Casting data types Fixing constants Summary 3 Performing operations Doing arithmetic Assigning values Comparing values Assessing logic Examining conditions Setting precedence Summary 4 Making statements Branching with if Switching branches Looping for Looping while Iterating for each Summary 5 Devising methods Creating function Passing arguments Overloading methods Refactoring code Summary 6 Handling strings Discovering string features Manipulating strings Joining and comparing strings Copying and swapping strings Finding substrings Formatting strings Formatting date strings Summary 7 Accessing files Writing a file Appending to a file Reading text and lines Streaming lines Manipulating input and output Summary 8 Solving problems Detecting real-time errors Fixing compile-time errors Debugging code Setting breakpoints Catching run-time errors Getting help Summary 9 Creating objects Encapsulating data Creating multiple objects Initializing class members Inheriting class properties Calling base constructors Hiding base methods Directing method calls Providing capability classes Employing partial classes Summary 10 Controlling events Starting a Forms project Adding visual controls Writing functional code Gathering text entries Ticking option boxes Showing user messages Calling system dialogs Creating application menus Making menus work Importing audio resources Summary 11 Building an application Planning the program Assigning fixed properties Designing the layout Setting dynamic properties Adding runtime function Testing the program Publishing the application Summary 12 Targeting devices Starting a Universal project Inserting page components Importing program assets Designing the layout Adding runtime function Testing the program Adjusting the interface Deploying the application Summary 1 Getting started Welcome to the exciting world of C# programming. This chapter introduces the Visual Studio Integrated Development Environment and shows you how to create a real Windows application. Introducing C# Installing Visual Studio Exploring the IDE Starting a Console project Writing your first program Following the rules Summary Introducing C# The introduction of the Microsoft .NET framework at the Professional Developers Conference in July 2000 also saw Microsoft introduce a new programming language called C# (pronounced “see-sharp”). The name was inspired by musical notation where a # sharp symbol indicates that a written note should be a semitone higher in pitch. This notion is similar to the naming of the C++ programming language where the ++ symbol indicates that a written value should be incremented by 1. • C# is designed to be a simple, modern, general-purpose, object-oriented programming language, borrowing key concepts from several other languages – most notably the Java programming language. Consequently, everything in C# is a class “object” with “properties” and “methods” that can be employed by a program. • C# is an elegant and “type-safe” programming language that enables developers to build a variety of secure and robust applications. You can use C# to create Windows client applications, XML web services, distributed components, client-server applications, database applications, and much, much more. • C# is specifically designed to utilize the proven functionality built into the .NET framework “class libraries”. Windows applications written in C# therefore require the Microsoft .NET framework to be installed on the computer running the application – typically an integral component of the system. The source code of all examples in this book is available for free download at www.ineasysteps.com/resource-center/downloads The Microsoft .NET Framework Each version of the Microsoft .NET framework includes a unified set of class libraries and a virtual execution system called the Common Language Runtime (CLR). The CLR allows the C# language and the class libraries to work together seamlessly. To create an executable program, source code written in the C# language is compiled by the C# Compiler into Intermediate Language (IL) code. This is stored on disk, together with other program resources such as images, in an “assembly”. Typically, the assembly will have a file extension of .exe or .dll. Each assembly contains a “manifest” which provides information about that program’s security requirements. When a C# program is executed, the assembly is loaded into the Common Language Runtime (CLR), and the security requirements specified in its assembly manifest are examined. When the security requirements are satisfied, the CLR performs Just-In-Time ( JIT) compilation of the IL code into native machine instructions. The CLR then performs “garbage collection”, exception handling, and resource management tasks before calling upon the operating system to execute the program: As language interoperability is a key feature of the Microsoft .NET framework, the IL code generated by the C# Compiler can interact with code generated by the .NET versions of other languages such as Visual Basic and Visual C++. The examples throughout this book demonstrate Visual C# program code.