Step by step android application

My First App: How to Create Your First Android App Step by Step

To create a native Android app, one that can directly use all the features and functionality available on an Android phone or tablet, you need to use the Android platform’s Java API framework. This is the API that allows you to perform common tasks such as drawing text, shapes, and colors on the screen, playing sounds or videos, and interacting with a device’s hardware sensors. Over the years, the Android API framework has evolved to become more stable, intuitive, and concise. As a result, being an Android developer today is easier than ever—even more so if you use Android Studio, the official tool for working with the framework.

In this tutorial, I’ll show you how to create your first Android app. While doing so, I’ll also introduce you to important Android-specific concepts such as views, layouts, and activities.

We’ll be starting from scratch to create a very simple app in this tutorial. If you prefer writing less code or need to develop your app as quickly as possible, however, consider using one of the native Android app templates available on CodeCanyon.

Using an app template, you can have a polished, ready-to-publish app in just a matter of hours. You can learn how to use an Android app template by referring to the following tutorial:

Prerequisites

To be able to follow along, you’ll need:

• the latest version of Android Studio
• a device or emulator running Android Marshmallow or higher

If you don’t have Android Studio, do refer to the following tutorial to learn how to install and configure it:

1. Create a New Project

You’ll need an Android Studio project to design, develop, and build your app. So launch Android Studio and click on the Start a new Android Studio project button.

On the next screen, choose Add No Activity because we don’t want to use any of the templates offered by Android Studio. Then press Next to proceed.

You’ll now see a form where you can enter important details about your app, such as its name and package name. The name is, of course, the name your users will see on their phones when they install your app.

The package name, on the other hand, is a unique identifier for your app on Google Play. You must follow the Java package naming conventions while specifying it. For example, if your app’s name is MyFirstApp and you work for an organization whose website address is example.com, the package name would ideally be «com.example.myfirstapp».

Next, you must decide the programming language you want to use while coding the app. For now, select Java and press Finish.

Android Studio will now take a minute or two to generate and configure the project.

2. Create an Activity

An activity is one of the most important components of an Android app. It is what allows you to create and display a user interface to your users. An app can have one or more activities, each allowing the user to perform an action. For example, an email client app can have three activities: one for the user to sign up, one to sign in, and one to compose an email.

To keep this tutorial simple, we’ll be creating an app with just one activity. To create the activity, in the Project panel of Android Studio, right-click on app and select New > Activity > Empty Activity.

In the dialog that pops up, type in MainActivity as the name of the activity, check the Launcher Activity option, and press Finish.

Checking the Launcher Activity option is important because it is what allows your users to open the activity using an Android launcher. As such, a launcher activity serves as an entry point to your app.

3. Create a Layout

Each activity usually has at least one layout associated with it. When you created your activity in the previous step, you also generated an empty layout for it. To take a look at it, open the activity_main.xml file.

An activity’s layout primarily consists of views and view groups. A view, sometimes referred to as a widget, is an individual component of your user interface. Buttons, text fields, labels, and progress bars are common examples of views. A view group is a component that can serve as a container for views. Usually, view groups also help you position and set the dimensions of your views.

ConstraintLayout is one of the most powerful and flexible view groups available today. By default, it is the root node of your activity’s layout XML file. It looks like this:

We’ll be creating a simple clock app in this tutorial. In addition to the local time, it will be able to show the current time in two different countries: India and Germany.

To allow the user to choose the country they’re interested in, our layout will have two Button views, one for Germany, and one for India. And to actually show the time, our layout will have a TextClock view.

Accordingly, add the following code inside the ConstraintLayout :

Note that each view must have the layout_width and layout_height properties. They decide how large the view is. Other properties such as layout_constraintBottom_toBottomOf and layout_constraintLeft_toLeftOf are necessary to position the view. With the above code, the TextClock view will be placed at the center of the screen, and both the Button views towards the bottom of the screen.

By default, the TextClock view only shows the hours and minutes. The format12Hour property, however, allows you to change that. In the above code, its value is set to h:mm:ss a . This tells the TextClock view that it should display the hours, minutes, seconds, and also an AM/PM suffix.

Also note that each Button view has an onClick property. This property is used to assign click event handlers to the buttons.

The handlers don’t exist yet, but you can ask Android Studio to generate them for you. To do so, hover over the name of the handler until you see a red light bulb appear beside it. Then click on the light bulb and select the second option, the one with the yellow light bulb.

At this point, you can try pressing Shift-F10 to run the app. If there are no errors in your XML code, you should see something like this on your phone or emulator:

Although the buttons don’t work yet, the TextClock view should show the local time, updating itself every second.

4. Implement Event Handlers

When you generated event handlers for the two buttons, Android Studio added two methods to your activity’s Java file, MainActivity.java. If you open it, you should find the following code in it:

Inside the event handlers, all we need to do is change the time zone of the TextClock view. But how do you reference a view that’s in your layout XML file from inside your Java file? Well, you just use the findViewById() method.

Once you have a reference to the TextClock view, you can call its setTimeZone() method to change its time zone. So add the following code inside the onClickGermany() method:

Similarly, add the following code inside the onClickIndia() method:

If you’re wondering what R is, it’s an auto-generated class that contains, among other things, the IDs of all the views you have in your layouts. The findViewById() method expects you to use this class while passing an ID to it.

At this point, you can press Shift-F10 again to re-run the app. You should now be able to click on the buttons to change the clock’s time zone.

Conclusion

You just created your first fully functional, native app for Android! I encourage you to make a few changes to it. For instance, you could try using other time formats or time zones. You could also try changing the positions of the buttons and the clock view.

There are dozens of views and view groups you can use to create your apps. Do refer to the official documentation to learn about them.

Android App Templates and UI Kits From CodeCanyon

You may have noticed that our app looks very plain and simple. That’s because we’re using the default theme, without applying any styles to our views. CodeCanyon is full of Android UI kits that offer beautiful, hand-crafted styles you can apply to your views.

The kits generally also have several custom views and layouts. You can refer to the following articles to learn more about them:

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Step by step android application

Step By Step — Smart Kids Gps Watch
Версия: 2.2.5

Последнее обновление программы в шапке: 03.04.2021

• Приложение для родительского контроля GPS смарт-часов Smart Baby Watch и других совместимых GPS устройств, а также детских мобильных телефонов и планшетов на платформе ANDROID, которое выводит их работу на новый уровень точности!
• Step By Step — продукт, разработанный с участием Wonlex и других заводов производителей, на основе миллионов пожеланий пользователей GPS трекеров во всем мире.
• Умные GPS часы для детей Smart Baby Watch уже давно продемонстрировали свою эффективность и Step был создан для того, чтобы работа GPS устройств стала максимально стабильна и удобна.
• Step имеет самый широкий функционал из представленных приложений на рынке и должен стать лучшим спутником ваших Smat Baby Watch:
  • GPS ЛОКАТОР — для точного определения местоположения детских gps устройств в режиме онлайн.
  • ИСТОРИЯ МАРШРУТОВ — отслеживание истории перемещений ваших умных устройств с gps.
  • ОБРАТНЫЙ ЗВОНОК — чтобы слышать звук вокруг детских смарт часов.
  • ГЕО-ЗОНЫ — для контроля входа и выхода ребенка из безопасных зон на карте.
  • КНОПКА СОС — для своевременной подачи ребенком SOS сигнала если нужна помощь в экстренной ситуации.
  • ЧАТ С РОДИТЕЛЯМИ — для общения всей семьей.
  • ПООЩРЕНИЯ — для отправки мотивирующих сердечек.
  • СНЯТИЕ С РУКИ — для своевременного оповещения родителя о том, что умные часы были сняты с руки.
  • НАПОМИНАНИЯ — для своевременных оповещений малыша о запланированных действиях, чтобы ничего не забыть.
  • АКТИВНОСТЬ — шагомер для контроля физической активности ребенка и истории ее изменений.
  • МАРШРУТ — для построения оптимального маршрута до нужного устройства и навигатор пешком, на автомобиле или общественном транспорте.
  • ВСЕ УСТРОЙСТВА НА ОДНОЙ КАРТЕ — одновременный контроль геолокации всех детских GPS трекеров, часов или телефонов на ANDROID на одной карте.
• Приложение подойдет для контроля и настройки любых устройств Smart Baby Watch, Smart Age Watch, Smart Pet Tracker, Smart Tracker, GPS-ошейников для животных и других аналогичных устройств, также вы можете подключить мобильный телефон или планшет ребенка на платформе ANDROID и использовать его в качестве объекта наблюдения!
• Список поддерживаемых производителей GPS часов:
• Wonlex, JET KID, SETRACKER, ГДЕ МОИ ДЕТИ, KidControl, AIBEILE, MyFrap, АСТЕРИУМ, GOGPS ME, КНОПКА911, КНОПКА ЖИЗНИ, Smart Baby Watch, KiDSnav, Ergo, Tiroki, Wokka Lokka, Pax+, Motto, Titan Watch, КАРКАМ, LEMFO, Noco, МАЯК, GINZZU, Tesla Nautilus Junior, Prolike, TipTop, Palmexx, YQT, Wochi, Wise, GOGPS, Sentar, SMARUS, Polaroid, Atrix, Denco, и многих других аналогичных.
• Список поддерживаемых моделей GPS часов:
• Q50, SBW X, SBW 1, SBW One, A9, A16, A19, A20, A20S, Q7, Q8, Q9, Q10, Q11, Q12, Q15, Q60, Q60s, Q65, Q66, Q70, Q75, Q80, Q90, Q90s, Q100, Q100s, Q120, Q121, Q150, Q150s, Q200, Q200s, Q360, Q300s, Q500, Q520, Q520s, Q528, Q528s, Q529, Q610s, Q730, Q750, Q1000, Q1000s, Gw100, Gw100s, Gw200s, Gw300, Gw300s, Gw400, Gw400s, Gw400x, Gw500, Gw500s, Gw600, Gw600s, Gw700, Gw700s, Gw900, Gw900s, Gw1000, Gw2000, Gw4000, G10, G36, G36s, G72, G100, G300, G300s, G600, G600s, G700, G900, G900s, G900a, Ew100, Ew200, Ew100s, T58, T7, T100, T529, TW6, i8, i365, iq100, iq300, iq400, iq600, L70, L70s, TD-02, TD-05, TD-10, W8, W9, W10, W12, W15, WS, W20s, S200, S01, S02, S03, S04, S4, S6, S7, S8, S9, D7, DF25, DF25G, DF27, DF27G, DF33, D99, D100, D100s, D200, GZ-501, GZ-502, GZ-503, GZ-505, GZ-507, GZ-511, GZ-521, GZ-751, JM13, GOZO, ZoOmix, SW800, WG-SW03, Smart Pet Tracker PT01, PT02, K6, K10, K911, K917, K010, V6G, FA23, E529, KT01, KT02, KT03, KT04, KT05, KT06, KT07, KT08, KT09, KT10, KT11, KT12, Y81, Aimoto Start, Aimoto Ocean, Aimoto Sport, Aimoto Disney, Aimoto Marvel, JET KID START, JET KID NEXT, JET KID SMART, JET KID SCOUT, JET KID SPORT, JET KID CONNECT, JET KID GEAR, JET KID SWIMMER, JET KID MY LITTLE PONY, JET KID TRANSFORMERS, Polaroid moji, GSMIN BW1 и многие другие аналогичные.

Платформа: Android
Русский интерфейс: Да
Разработчик: ООО «Компьютерные системы»
Страница приложения в магазине: Step By Step

По вопросам наполнения шапки обращайтесь в QMS к Модераторам раздела или через кнопку «Жалоба» под сообщениями, на которые необходимо добавить ссылки.

Сообщение отредактировал Lеshij — 20.05.21, 08:27

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