Develop a mobile application for iOS. How to learn to program for iOS

Useful tips

iOS is the operating system that Apple smartphones run on. To purchase games or applications, use a proprietary digital shopping platform App Store. If the developer’s product turns out to be successful (will be in demand among users), then even for one program you can earn good money. On average, developers of popular iOS applications earn several thousand dollars a month.

Process of creation

The algorithm for creating a program or game has the same concept regardless of the platform, so it is extremely important to adhere to development rules. By skipping this or that step, the developer risks getting a failed project at the initial stage. Let's take a closer look at the algorithm for creating a digital product:

Creating a product concept– the first stage, requiring analysis of trends in digital store App Store. When creating a project, the developer must clearly outline the target audience. For the analytical stage to be successful, look at which applications, programs, games, etc. are in the top of the App Store. In addition, find out what is installed on the smartphones of your acquaintances, friends, and relatives.
Technical base– first you need to learn the Objective-C language, which is used in writing programs for iOS. For beginner programmers, it is recommended to familiarize yourself with Pascal language and other languages: C, Java.
Tools– development environment, special text editor and graphic editor.
Creation and testing programs.
Marketing promotion.

Step-by-step creation of the utility

Each user has the opportunity to independently create an application for iOS without additional financial investments and professional knowledge. There is a special XCode development environment that allows you to work directly on your phone. If you need to write mobile applications on a Windows computer, you will have to install special virtual machines. For example, VirtualBox and VMware. Let's take a closer look at the official method:

Install on your smartphone XCode development environment. The supplement is in official store App Store OS and has free system distribution. If the program is installed on your phone, check it for updates.
Once you've sorted out the preparatory settings, log into XCode. To create a new project, use the tab File. Next, a sub-item will open where you need to select commands New And Project.
The next step in creating an iPhone application is choosing platform and thematic type future utility.
Specify brief information about the software being created.
Next you need to press the key New Folder. A folder is created here where auxiliary files for the program will be stored.
In the next window, uncheck the item and activate the command Create. Thanks to these manipulations, the user will be taken to the start work panel.
Click on the button called storyboard. It is located on the right side of the interface. Drag an element with the name to the main field Label. Don't forget to add introductory text in the line Hello_world(any other text is possible).
Be sure to come up with icon for the utility. Upload your icon to mapappicon.com.
After a short processing of the request, indicate address Email , where they will send an archive with icons.
Return to the XCode development environment. Now on the left side of the interface, find a section called xassets.
Open the archive from the mail (where the icons were sent) and drag them into the window located in XCode.
Select one of the device emulators, and then click on the command launch the program(the icon is indicated as a black triangle), turning on Mac Developer Mode.
Repeat startup attempt waiting until iOS loads on the emulator.
Make sure that the utility works.

This way you can create your application from scratch.

Popular services for creating applications

We offer a selection of services that will help you make iOS applications yourself.

Apps Globus

The Apps Globus project is a universal application designer that is suitable for Android and iOS mobile operating systems. It features a convenient user interface. Thanks to the built-in modules, significantly simplifies the development process. Apps Globus supports up to 60 built-in modules, including:

Apps Globus is distributed by paid subscription. Users who want to test the application can use the 5-day demo version. Monthly subscription is provided in three types: “ home page», « studio" And " business" The difference between subscriptions is the price and number of developed applications. There is also a version that requires a one-time payment of 20,000 rubles. In addition to unlimited use, it offers source codes and assistance in setting up the utility.

App2b

The App2b project offers a multifunctional designer that can be used not only to create applications for iOS, but also for Android platforms. This constructor creates a commercial or information content. That is why the service has built-in template library to quickly create a convenient application yourself.

Like other similar projects it is distributed by paid subscription. The main difference from other designers is the only payment method in the form of a one-time payment in the amount of 9,900 rubles.

The project is the only free designer for creating websites and applications. The program is comprehensive solution for online business. Allows you to create unique pages, virtual stores, electronic magazines. Distinctive feature constructor is lack of prepared templates. Instead, flexible tools that do not require programming knowledge are used. Because of this, any program created in New Digital Times looks like the author's work.

The designer is a multimedia tool aimed at creating business applications of various types: information panels, online stores, restaurant menus, etc. For the convenience of users there are built-in templates for programs and synchronization with social networks and other popular services.

Sold in several variations: for independent use And affiliate program. Distributed in two types of subscription: monthly and annual. In addition, on the site you can hire people to create programs.

February 9, 2015 at 5:54 pm

Creating an iOS application. From idea to result

iOS development

It all started when I looked around and, not seeing the car of my dreams, decided to design it myself
Ferdinand Porsche

Hello, Habr. I want to tell you how I created my first iOS application and what came out of it.

Idea

The idea for the application arose naturally: create something that you would be happy to use yourself. I write notes all the time. After all, every busy person has a certain set of facts that he receives during the day, and which are worth remembering. And since everyone forgets (and that’s normal!), there’s no better solution than just writing it down. I always felt some kind of inconvenience when working with the note-taking applications presented in the AppStore. Excessive complexity in management, the presence of unnecessary categories, a plethora of additional information - all this prevents the application from performing its main function. Plus, many of these things just look ugly.

Therefore, putting all bets on simplicity and convenience, I began to create a concept. Application model with a single list of notes. Everything in one place, what could be simpler? If something is of great value or relevance, it is not necessary to attach a label to it, because it is enough to simply move more important note to the top of the list. Old and unnecessary entries will gradually fall down and will subsequently be removed by the user.

Functional

After the concept was thought up, I wrote down the main functionality - those things that I would like to focus on in management:

Enough standard functionality for this kind of application, you agree. But this is just the tip of the iceberg, the devil is in the details.

Tools

Before writing the code in Xcode, I completely recreated appearance applications in vector editor Sketch. This program is great for quickly creating layouts. There are a lot of plugins available for this application, among them there is Sketch Preview - viewing the artboard directly on the device through the Skala Preview program. You just need to download the free Skala Preview programs to your computer and mobile device and install the plugin. After that, select the desired artboard, press the Command+P combination, and within a second the appearance of the application is transmitted to the device.

In addition, the application is very convenient for creating screenshots for publication in the AppStore. For each screen size, a different set of artboards was created, along with the use of styles; the time spent on formatting was minimal. But about the publication a little later.

Development

In the application, I used only two controllers - one directly for all, all, all notes, the other to display a small tutorial when first launched. I organized work with the database using the CoreData framework.

After creating the basic functionality (creating, deleting, editing notes), I decided to improve each of these functions.

Agree, text editing in iOS is implemented quite inconveniently. If you make a mistake in a word, to move the cursor to the desired position, you must touch and, without removing your finger from the screen, try to get into the selected area. In addition, after correcting the error, you need to return the cursor back to the end of the line. In my application, I decided to rework the mechanism for moving the cursor: in order to make a change to a word, you just need to swipe in the area between the keyboard and the phrase being typed without blocking the view of the text.

I decided to implement the animations of deleting and moving to the top myself, and to bring the visual support as close as possible to real life. Something has acquired a higher priority - swipe to the right and the note moves to the top of the list. To delete, swipe left and the strikethrough animation will show how long you need to extend the swipe to complete the deletion. If you accidentally delete it, you just need to shake the device (“Shake”), and the note will return to its original place.

In order to highlight the note, I used LongTapGesture and the application's three main colors - white, blue and red, which formed the main color palette.

I decided to make the transition between day and night themes automatic - why has no one yet thought of changing the appearance depending on the position of the sun in the sky? It's very simple - after dark and after sunrise, the theme changes, and the user does not need to be distracted from taking notes, because the application will always automatically adjust to the surrounding conditions.

Naming

The name of the application is the most an important part during development, this is the first thing the user sees in the store. There is information about this on Habré. I decided to approach the selection of the name thoroughly: first, I went through the list of the 1000 most popular words in the English language and wrote down all sorts of combinations that would be suitable for the name of a mobile note-taking application; besides, I wanted to keep it within 8-10 characters. But at the same time, I didn’t want to choose the name SuperNotes or NotesPlus etc, I wanted something new. I liked the combination mad note, which I accidentally came across in Urban Dictionary:

mad note - excellent, entertaining, surprising, unexpected or awesome

The slogan immediately appeared: MadNotes - Note your passion. Since I already had a palette of primary colors ready (white, blue, red), I decided to immediately come up with a suitable icon. The situation with logos for applications of this kind is deplorable:

Since notes on paper are written with a pencil or pen, I decided to display this on the icon - a pencil rotated at an angle of 45 degrees. It turned out like this:

Result

Since the project was initially conceived as a design project, I decided to participate with my application in the all-Ukrainian competition Ukrainian Design Awards: The Very Best Of in the Digital Design category. There were several weeks left before the competition, during which time I managed to make a publication on Behance, where I visually showed all the main functions of the application, and also recorded a video preview.
Since the winners of the competition are not disclosed until the very last moment, it was incredibly pleasant to see my work at the exhibition of the winners' works - the jury saw and appreciated the main concept - minimalistic and, at the same time, functional application for taking notes.

The application has been in the AppStore for several months, during which time I made six updates and rewrote the code in Swift. IN latest version(1.2) added synchronization with iCloud, so the notes have already moved to the cloud.

Thank you for your attention.
Note your passion

Developing applications for iOS can be not only very exciting, but also quite profitable. You just need to create a high-quality Soft that is relevant for users of Apple devices, put it on the AppStore and enjoy the fruits of your activity, that is, make a financial profit.

Today, many enthusiasts are looking for an answer to the question of how to create an application for iOS on Windows. Official ways there is no solution to this problem. Some software solving the problem creating applications for iOS, yes. However, its use leads to a number of difficulties.

Therefore, everyone who decides to seriously engage in the development of programs and games for mobile devices from Apple, you should get a computer with OS X version 10.8 or higher.

How to create an application for iOS: sequence of actions

In order to start creating applications for iOS, you will need to undergo certain training, namely:

Install Xcode. It is provided free of charge by Apple and can only be installed on OS X. There are no methods for running this software on Windows and Linux.
Install functional text editor, for example JEdit or TextMate. This will significantly simplify the performance of certain actions, for example, writing code.
Install a vector graphics program. It is necessary for developing games and programs with images and designs. You can use software such as Inkscape, Adobe Illustrator and CorelDraw. Their free analogue is the DrawBerry program.
Learn the basics of Objective-C - a programming language without which it is impossible to create games for iOS and functional programs. Although it is possible to create simple software without this programming language, it will not be possible to make it functional. (If there is no desire to learn Objective-C, then you will have to use the services of freelancers who will do part of the work on developing applications for a financial reward).
Create a developer account. To do this, you will have to pay $99 (fee is charged every year) and enter your tax information.
Download and review test applications. This will give you a hands-on iOS development experience.

A high-quality software product is a product that is based on a clearly formulated concept. That is why it is necessary to start creating an iOS application by planning it. That means:

Defining the concept of the future program (design, functionality, main actions, operation scheme of the future software - all this must be clearly thought out and approved). If the task is to create a game for iOS, then its genre must be chosen, the storyline, characters, and so on must be thought out.
Select a target audience, which greatly depends on the functionality of the software.
Select specific tasks that the software being developed will solve.
Think over the user interface, which should be such as to facilitate maximum quick solution tasks to be applied. It is better to work through several options, a visual study of which will help determine the final choice.

Now you can start directly developing mobile applications for iOS. To do this, in the program for creating applications for iOS (Xcode), you need to start new project and provide all the required information. The development process then looks something like this:

Creation of a Storyboard, which is necessary for visually displaying all screens of the future application, as well as transitions between them.
Assigning a Storyboard to the created project. This is necessary so that the selected interface is loaded when the program starts.
Creating the first screen using the view controller. There is a wide variety of controllers that have already been created, and they themselves are necessary for the program to “understand” exactly how to display content to the user.
Adding interface objects. Developing an application for iOS is impossible without using functional interface elements such as text fields, various labels, navigation, buttons, and others. All of them are in the Objects Library list.
Changing the properties of added objects. This is necessary to give the program being created individuality. Without this, it will not be possible to create a popular program for iOS.
Adding new screens. Almost every modern application for mobile devices from Apple has several user screens.
Adding a functional navigation bar, which is necessary to move users between program screens.
Assigning the functionality of the created buttons.
Creating the ability to process data by the program. This step involves using the language Objective-C programming, with the help of which the application will be able to store and process data entered by the user, as well as perform other functions.

The final stage of creating an iOS application is testing it. To do this, you need to build the program using XCode (the “Build” button), and then check its functionality on the emulator built into the software and on your own Apple device.

Whenever various errors or the application crashes, you need to find out their causes and eliminate them.

Also, the created iOS application can be sent to other users for testing, for which you need to create an Ad-Hoc certificate on the iOS Dev Center website. Users will be able to give large quantities reviews that will help make the program more stable, functional and useful.

It is important to know! The created Soft can pass Apple certification only if it is optimized for iOS 8 version and a retina display.

After testing and debugging the application created for iOS, you can begin final compilation and publication via the web interface of the iTunes Connect website. To do this you will have to perform several steps:

come up with a name for the application;
enter detailed information about it;
send the program to the appstore;
wait for him to check.

Now you know how to create an application for iOS, and you can safely begin to implement your idea. However, remember that it is better to start with a small program that implements simple tasks.

Developing several such applications for iOS will allow you to understand the principles of creating programs for Apple devices, as well as gain the skills to create more complex applications.

At the end of last month, developer Richard Felix published an entertaining one in which he tried to explain as clearly and concisely as possible how to create successful application for iOS. In particular, he shared useful tips for beginning developers, with their own observations in terms of program design and latest trends in the App Store.

Richard knows all the intricacies of development from personal experience, since over the past few years he has created a number of popular applications for modern mobile platforms and the web (Are My Sites Up, Stunning, Dispatch and others).

So, at some point in your life, you decided to become a developer and try your hand at creating your own iOS app. You're afraid that you'll spend a lot of time (and money) developing a program that no one will use. You dream of creating an app that will be actively selling a year after its release, but you have no idea how to do it. The tips described below will help you achieve your goals.

Find an original idea

On each Apple presentations announces million-dollar sales of iOS devices and fantastic App Store records. Guided by this fact, many novice developers mistakenly assume that creating another banal email client or photo editor will allow them to earn millions of dollars (in their opinion, this does not necessarily require climbing to the top of the Apple app store charts).

However, despite the prevalence of the iOS platform, this is a big misconception. Of course, in this case you will earn some money and recoup the development process, but to truly achieve meaningful success, your program must not only perform the stated functions, but also have some kind of original feature, a kind of zest that would distinguish it from hundreds of competitors and attract attention against the general background.

Research your target audience

The App Store offers anyone a real treasure in the form of charts of popular applications, on the basis of which you can decide on the category of the program, notice some points for yourself and find that very original idea.

At the moment, we can distinguish the following three categories of the most popular programs in the App Store:

Alternative applications for system programs iOS (improved calculators, calendars, email clients, photo editors, task lists, etc.). They are popular because many people face restrictions standard tools iPhone/iPad and want to expand the functionality of their devices. Apple creates programs for the masses (they are easy to use and intuitive), which is why more advanced users suffer (if you need more features, you will have to use a third-party application - and this is to our advantage).

Games, and a variety of them. Especially those that force you to share the application with friends and colleagues, which is much more valuable than any advertising banner.

Applications with a minimum number of functions that at first glance seem so elementary that many developers dismiss such ideas even at the stage of thinking about the project. A typical example is a program called Over, which allows you to add elegant captions to your photos. For an advanced user, Over may seem like a rather limited tool, but many beginners are completely satisfied with this “photo editor,” which is confirmed by good sales. It's amazing how the correct implementation of a single declared function can lead to a completely successful program.

Don't reinvent the wheel and update often

Many popular apps for iOS have achieved their success thanks to the following feature - they allow the user to quickly perform some action (process a photo, for example), but do not burden him with unnecessary functions and buttons. There is no need to reinvent the wheel and create a photo editor with music playback function.

Put yourself in the user's shoes, try to focus on the features that will really useful. It is not at all necessary to implement all your ideas in the first version; leave minor ideas for future updates of the application. After the program is released in the App Store, you will have a lot of user reviews, based on which you can draw conclusions about the need to implement this or that function.

In addition, regular updates of the application allow your product to constantly be heard, “flash” before the eyes of potential buyers in the blogosphere.

Draw a colorful icon

A beautiful icon is the key to the success of any application ( so anyone? - editor's note). Holding in your hands iPhone or iPad, the user always wants to see high-quality graphics and a “luscious” design on his display, which, as they say, is pleasing to the eye. People will be more likely to pay attention to the program if the design department spends enough time and effort creating an attractive brand icon. Ultimately, this should help your app reach the top of the App Store charts.

On specialized sites like

The profession of a programmer is one of the most prestigious and in demand, that’s a fact. The software development industry has its niches. Of these, the fastest growing, and at the same time the most highly paid, is software development for mobile devices. As you know, it just so happened that, leaving their competitors far behind, three constant rivals took the lead. The trick is that one of these three is the undisputed leader, while someone always catches up.

In the segment mobile technologies, without a doubt, Apple is in the lead with its iPhone smartphone. At a presentation held in September, the Cupertino company demonstrated the 7th version of the mobile device. Along with it, Apple introduced a new version of its mobile operating system. iOS systems 10. Now it is the most significant operating system in the world, like its predecessors. It follows that learning iOS development is the best investment of time and money.

Apple ecosystem

Today we will develop a simple mobile application for iOS. Of course, a native Mac is best suited for this. But if you are a Windows supporter or you simply don’t have a Mac, you can install operating system macOS under virtual machine on Windows. On the Internet, it will not be difficult for you to find a version of macOS specially tailored for PC, popularly called Hackintosh. Feel free to install it on a VMware virtual machine, VirtualBox - your choice. Let me warn you right away that the PC keyboard does not have some of the keys that are on the Mac keyboard, and many of their combinations cannot be pressed in Hackintosh. This pretty much spoils the mood. Otherwise, all the operations described below can be successfully performed on Hackintosh.

Required knowledge

To program in general and for iOS in particular, you need to know quite a lot. Mathematics and logic may not be needed at first, but they will be in demand later. Modern technology has eliminated the need for a programmer to have a thorough knowledge of computer architecture, but understanding basic mechanisms such as number systems, their conversion, the speed of subroutines or the efficiency of algorithms (big O) is necessary.

At a higher level, an iOS developer needs to have a deep knowledge of the macOS operating system and iOS itself. You also need to master the Apple programming language. Knowledge of Delphi, C++, C# or VB.NET will not help you much. Apple has its own ecosystem with its own languages: Objective-C and Swift. Of course, knowledge of C++ has never harmed anyone; programs and inserts based on it are found everywhere, even at Apple. But the most used by definition is Objective-C, simply because it appeared much earlier (in the mid-eighties of the last century), while Swift only two years ago (in 2014). Apple has high hopes for new language and invests a lot in it. Objective-C is used to support the old software, and the new one is written in Swift. So it's good for you to know both.

In order not to waste time, all these programming languages can be learned under the strict supervision of teachers on the website.

Development Tools

As you know, the main developer tool for macOS and with it iOS is the programming environment Xcode. It includes tools for creating applications for Mac, iPhone, iPad, Apple TV, Apple Watch. All Apple platforms. Xcode contains the Interface Builder, a code editor that supports all modern code tools. In addition, without leaving Xcode, you can test the application; if it is developed for an external device, then it can be run in an emulator.

The system includes emulators of all devices, new versions of which can be downloaded. In addition, Xcode contains graphical tools for analyzing application performance, including tools for diagnosing CPU load, storage usage (HDD, SDD and others), load on the graphics adapter (from the OpenGL side).

On September 13, a new, hotly anticipated version of the development environment 8.0 was released. Stable versions can be downloaded for free from the App Store. Alphas and betas are distributed by developer subscription. The eighth version includes: a new version of the Swift 3 language, the Swift Playground learning tool for iPad, a new version of Interface Builder, which has become faster and allows you to view the application layout on different platforms, without having to deploy the application itself to the simulator.

Xcode 8 can be used to develop applications for macOS Sierra, iOS 10, watchOS 3 and tvOS 10. All SDKs are available. New versions of operating systems began to appear consistently right after Apple’s presentation, which took place in early September.

Objective-C language

Let us briefly recall the basic information about the language. Objective-C - Object Compiled language oriented programming used to write applications for Apple systems. It is a superset or, in other words, an add-on to C, inheriting from the latter syntax, data types, methods of monitoring the progress of program execution and adding to it the capabilities of object-oriented programming - a description of classes and methods.

As in C++, in Objective-C the central role is played by objects, which are associated with four paradigms: abstraction, encapsulation, inheritance, polymorphism. C++ is a strongly typed language, while Objective-C is weakly typed or has a dynamic data type system. Like Smalltalk, Objective-C sends messages to objects. This is an exceptional opportunity dynamic languages, because the type of objects is checked at runtime, not at compile time.

The description of the Objective-C language takes up more than one voluminous volume. Therefore, in order to gain objective knowledge, it is convenient to take the “” course. An entire section of the course is dedicated to this language.

iOS application development

As a sample we will develop a very simple application. Let us not deviate from the sacred tradition, let us greet the world. However, taking into account the fact that we graphic application, we will diversify it a little: we will add a button, when clicked, we will display or hide the inscription “Hello, World”.

Launch Xcode, in the window that appears, select Create new project or in the main menu File -> New -> Project. The next window will ask you to select the target platform and application type.

IN in this case we are interested in iOS platform. There are seven types of applications to choose from. Six of them are templates for typical applications of the iOS operating system, containing a different set of components by default. The seventh type is play.

Application Types

The Single View Application template is designed for a simple single-screen application. The preset includes a View Controller component, which allows you to customize the appearance of the application using the Interface Builder form designer.
Master Detail Application creates an application that displays a collection of objects in a table view. After selecting one of them, they are shown details about this object. The first view is the master, the second is the detailing.
Page-Based Application creates applications that have multiple screens, like pages in a book. Consequently, e-readers are created from this blank.
Tabbed application allows you to create applications where each screen can be switched to at any time, that is, each screen has its own button to activate it, on which the title is displayed. An example is iTunes.
Game is used to create a game template. There are four frameworks to choose from for creating a game: SpriteKit, SceneKit, OpenGL ES, Metal. Let's look at them briefly.
SpriteKit is a system for 2D rendering and animation of textured rectangles - sprites. When displaying frames, a standard loop is used, the frame is displayed after all the contents of the scene have been processed.
SceneKit is a high-level framework for rendering 3D graphics without OpenGL. It supports loading, manipulating 3D objects. It includes: a physics engine, a particle generator and easy way scripting.
OpenGL ES is a standard in computer graphics. Allows you to visualize 2D and 3D scenes. Allows you to describe the pipeline for a video card: vertices undergo transformation, are assembled into primitives, which are rasterized into a two-dimensional image and displayed on the screen. Programmable shaders can be included in the pipeline.
Metal is a low-level API that will allow you to get the most out of your video adapter. Debugged APIs along with precompiled shaders and multi-threading allow your game to rise to the top. new level productivity and quality.
Sticker Pack Application is a new type of application introduced in iOS 10 and Xcode 8. It is a set of simple or animated images used in the new iMessage. It does not require coding to create it.
iMessage Application is a new type of application that appeared in iOS 10 and Xcode 8. Allows you to create add-ons for iMessage, for example to purchase and download your sticker pack. You can also use the iMessage API to create your own analogue this application, including playing audio, video, using stickers and more.

Creating the first project

As a template for our application, we will select Single View Application. Since we will not be developing a large program, the funds provided by this provision will be enough for us. Click Next. On the next page of the wizard, you need to enter a project name, for example ShowLab. In the Language drop-down list, leave the default language selected - Objective-C. Next, in the Devices drop-down list, leave the Universal selection. Here you determine for which device (iPhone or iPad) the application is being created. The Universal clause means for both. Let's uncheck the Include Unit Tests and Include UI Tests boxes; we don't need any tests. Next. Select a folder to save the project. Now click the Create button.

As a result, a window will open with a list of all parameters applied to the project. In this window, you can change the parameters previously set in the wizard: orientation, target device, etc.

First we need to create the application interface. To do this, select the Main.storyboard file in the list on the left with one click (if this file is not visible, expand the contents of the ShowLab folder). To the right of the list, the entire window will be occupied by Interface Builder. The device layout will be displayed in the center. In the lower right corner of the window there is a component panel. Drag the Label and Button components from there onto the layout. Above the component panel is a list of properties. If you don’t have it, click the Show the Attributes Inspector button, located under the window title on the right side of the interface.

Select the Label component in the layout and configure it Text property: leave the Plain selection in the drop-down list, enter the desired inscription in the line below, in our case “Hello, World”. If the text does not fit within the borders of the label, change them by dragging the handles on the edges of the component. To centralize it horizontally, go to the Size Inspector page by clicking on the Show the Size Inspector button (to the right of Show the Attributes Inspector). On this page, from the Arrange drop-down list, select Center Horizontally in Container.

Now select the Button component, change its Text property to the desired label - Switch. You can center it in the same way as described above.

Creating a connection between graphic elements and code

IN Visual Studio(or Delphi) object in the code is created automatically the moment you place a visual component on the form. This doesn't happen in Xcode, but it doesn't cause problems.

Open the contents of the ViewController.h header file in a separate window by double-clicking on it. This file contains a declaration of an extension of the UIViewController class, marked with the @interface keyword. This feature was added to the second version of Objective-C. Now do this trick: move the mouse cursor to a component - a text label, hold down the Ctrl key and left button mice. Move the cursor to the window with the code (file ViewController.h), a blue line will follow the cursor. Release the mouse and key inside the ViewController interface description.

The Outlet creation window will appear.

This is a property of an object that refers to another object (in this case, a visual component). You need to enter the name of the Outlet object, by which you will access the visual component, let it be lab. Next, the object type is selected, it is selected correctly: UILabel.

Even lower in the Storage list, select the type of object reference: weak or strong. If you choose strong, then the object pointed to by the property will exist as long as the property points to it, in which case it will not be automatically deleted when it is no longer used. On the other hand, when a weak reference is in effect, the object can self-destruct. So, select the weak link type and click the Connect button. As a result, the following line will be added to the code:

@property (weak, nonatomic) IBOutlet UILabel *lab;

Let's make sure that Outlet is a property.

Now let's create an Outlet for the button. The algorithm remains the same. Only for the Name property you need to enter a different name, for example but. The line will be added to the code:

@property (weak, nonatomic) IBOutlet UIButton *but;

As a result, we have two pointers to visual components: lab and but - respectively, an inscription and a button. Now, using pointers, we can manipulate components in code.

Then you need to create a button click event handler. To do this, open the implementation file ViewController.m in a separate window. In exactly the same way as you dragged the line into the header file to create the outlet, from the button, drag the line into the implementation file and drop it to the closing command bracket - @end. A window for creating an event will appear, similar to the window for creating an outlet. You see the difference: a link to an object is created in the header file, a method is created in the implementation file.

Fill in the Name field, its value represents the name of the property - method. Let it be onClick. Leave the Type field value as default - id. In Objective-C this type is the ancestor of everyone else. In the Event drop-down list, the Touch Up Inside event is selected by default, which occurs when the pointer (mouse, finger...) is released over the button, that is, the final stage of pressing the button. That's what we need. In the Arguments list, we will leave the default value: Sender is the object that sent this signal, in our case it will always be a button. Click the Connect button. As a result, the following code will be added:

- (IBAction)onClick:(id)sender ( )

A minus at the beginning means a closed method (private). The IBAction keyword marks events (methods) visual components from Interface Builder.

Between the command brackets we will write the code that is executed when the button is pressed:

Lab.hidden = !_lab.hidden;

In this line of code we invert the value of the hidden property. It is of type BOOL, which has two values: YES - true and NO - false (somewhat unusual for Windows programmers, where true and false).

Pay attention to the underscore character before the name of the object - the label (_lab). Without it, compilation will fail. The underscore is added automatically for objects contained within other objects; that is, in this case, the lab object is contained in the ViewController object. Previously, this was a convention used to distinguish between objects declared as members of a class and local objects. And now this is a strict rule implemented in the language compiler.

Now you can compile the application and run it on the simulator. We chose the simulator for iPhone 7, included in Xcode 8. The compile and run button is a black rectangle and is located in the bar at the top of the interface.

After compiling the application, launching the simulator and loading our application, its interface will be displayed on the simulator screen: the inscription “Hello, World” and the Switch button. If you press the last one, the inscription will disappear; if you press it again, it will appear again.

We have made a very simple application to understand the essence of iOS development. You can learn more detailed information about creating iOS applications in Objective-C from the course by our friends from GeekBrains “”. The course devotes two months to learning this language. During the first month - introductory topics, and in the second - real coding of professional applications.

Swift language

IN 2014 Apple year introduced a new programming language - Swift. It quickly became the most talked about and fastest growing language in the world. It's reliable, safe, intuitive clear language for developing applications for operating systems macOS systems, iOS, tvOS and watchOS for the entire fleet of Apple devices. Swift- effective language programming. It's easier to learn than its predecessor, Objective-C, and Swift borrows some of its best ideas. At the same time, the developers have made the languages compatible, that is, one program can contain code in both Swift and Objective-C. There are billions of lines of code and hundreds of thousands of legacy programs written in Objective-C in the world, so its support will definitely not be abandoned.

When developing Swift, the goal was to create the most convenient system programming language - fast, safe and expressive.

The algorithm in Swift is 2.6 times faster than the same algorithm in Objective-C, and 8.4 times faster than in Python. Using Swift makes the program development process more flexible and convenient.

Thanks to its exponential development, December 3, 2015 Swift language has been contributed to the open source community. At the same time, Apple strictly monitors its development, organizing a committee for its development. Now Swift is available not only in Apple systems, but also on Linux. All additional tools for working with the language, including a debugger, standard library, package manager, are also free and open.

This language is the future. You can find out more detailed information about it from the mentioned course from GeekBrains “”, in which a whole month is devoted to learning this programming language.

App Store

Simply put, the App Store is a content store for the entire range of Apple devices. Here you can buy games and applications from both large companies and independent developers. Every developer, no matter what country he lives in, can sell or distribute his programs for free on this digital distribution platform. To start doing this, you need to register as a developer and buy a license to sell your applications. This is a fee for the service provided and development App store Store.

Results

We have developed a simple application for the iOS mobile operating system using the Xcode programming system along with the Objective-C language. Tested ready application on the iPhone 7 simulator. We learned how to build a user interface using Interface Builder, how to associate graphic elements with application code, and how to create event handlers. We got acquainted with the basics of Objective-C. In addition, we drew attention to the promising Swift language, used to develop powerful and secure applications for the Apple ecosystem.

However, the material studied is only the beginning. In order to intensively upgrade yourself in the direction of mobile coding and the development of actually selling applications, we recommend taking the “” course on our friends’ website.

This is a worthy course: if you take it, you definitely won’t waste your time. It starts with two detailed courses on the Java language, followed by learning basic programming for the mobile operating system Android system. Next is a course on databases in general and the SQL language in particular. Then an in-depth course on developing professional Android applications. After this, the vector of study will move towards Apple systems: two detailed courses on the Objective-C language and useful course by Swift.

The course lectures are taught by professional teachers with extensive experience in software development. If something is unclear, you can ask a question without delay. In general, learning on GeekBrains is a live process, you can communicate, ask questions, and help with answers. To test the acquired knowledge, teachers issue homework, which is then checked. After completing the training, you will have a guaranteed internship in an IT company. And then everything depends on you, if you show yourself as a competent specialist, you will be invited to work.

Special project with the company