Секундомер android studio kotlin

Chronometer

Компонент Chronometer находился в разделе Date в старых версиях студии. Позволяет пользователю запускать и останавливать начальный отсчёт времени, а также задавать время запуска таймера.

Основные методы:

• start() — запускает отсчёт времени;
• stop() — останавливает отсчёт времени;
• setFormat() — задаёт формат отображения времени. По умолчанию используется формат «MM:SS» или «H:MM:SS». Можно задать свой формат, при этом в строке format первое встреченное «%s», будет заменено на «HH:MM». Например: «Time: %s» будет выводить время «Time: 01:30»

Класс Chronometer имеет интерфейс OnChronometerTickListener.

Поместите на экран активности компонент Chronometer и три кнопки Старт, Стоп, Сброс.

Напишем код для запуска, остановки и сброса секундомера. Весь код сводится обработке щелчков кнопки.

В примере также добавлена реализация OnChronometerTickListener — когда секундомер отсчитает 5 секунд, то появится всплывающее сообщение.

Обратный отсчёт

В API 24 появился новый метод setCountDown(), позволяющий работать в режиме обратного отсчёта. Родственный XML-атрибут для него — android:countDown. Метод isCountDown() позволит узнать, в каком режиме работает хронометр.

Последний отсчёт

Читая документацию, наткнулся на новый метод из API 26 (Android 8.0 Oreo) — isTheFinalCountDown(). Я запустил этот код и чуть не упал со стула от неожиданности — неожиданно в телефоне заиграл видеоролик с песней «The Final Countdown/Последний отсчёт» группы «Европа/Europe». Разработчики развлекаются.

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How to make a Countdown Timer in Android using Kotlin

Today, I will show you how to build a timer that countdowns until an event (e.g. new year’s day or release date of a video game) using the Handler to update the TextView every second.

First, add a TextView in your layout, like that:

Then go to your Activity and create a method with a name updateTime() and set the current date:

Set the event date

Find how many milliseconds left until the event

Convert the milliseconds to days, hours, minutes, and seconds

Show the countdown timer in your TextView

Now, to call the updateTime() method every second, we’re going to use the Handler() class and repeat the handler every second (1000 milliseconds)

If you want to show different text after the event has passed, create a method with a name endEvent and pass the currentdate and eventdate.

After you have shown your text, stop the handler from repeating.

If you have any questions, please feel free to leave a comment below

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Секундомер на Android

Добрый день. Возобновил изучение платформы android. Возник такой вопрос. Есть два куска кода, вот собственно первый:

Проблема в том что они должны, как я понимаю, работать одинаково, но работает только пример под номером 2. Кто знает почему так?

1 ответ 1

1 фрагмент кода вызывается ровно 1 раз. Он вызывается через 1 секунду с помощью handler.postDelayed(. 1000) , отрабатывает и всё.

2 фрагмент кода вызывается сразу методом handler.post и в конце своей работы вызывает handler.postDelayed(this, 1000); т.е. вызывает сам себе через 1 секунду.

А в целом рекомендую ещё посмотреть на класс CountDownTimer , который делает в принципе тоже самое, но «из коробки».

Всё ещё ищете ответ? Посмотрите другие вопросы с метками android или задайте свой вопрос.

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How to create a simple countdown timer in Kotlin?

I know how to create a simple countdown timer in Java. But I’d like to create this one in Kotlin.

How can I do it using Kotlin?

6 Answers 6

You can use Kotlin objects:

I’ve solved my problem with timer in Kotlin like this:

I’ve used Coroutines for a timer.

Chronometer can be set to count down and it seems to me the easiest way.

Add the Chronometer view in your layout xml, example

Then in your activity or fragment:

If you want to show a countdown with days hours minutes and seconds

If you are navigating to another activity/fragment, make sure to cancel the countdown

51 days 17 hs 56 min 5 sec

Try to use objects, like this :

You have a little button «Convert from Java» on the top right that could be useful to you.

EDIT:

Do not forget to start this object when you need it, by adding .start() at the end of the declaration, or wherever in your activity / fragment :

22hr : 42min : 51sec //when less than 4hr are remaining

1day : 23hr : 52min : 44sec // in other cases

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Tutorialwing

In this article, we will learn about android ChronoMeter using Kotlin. We will go through various example that demonstrates how to use different attributes of ChronoMeter. For example,

In this article, we will get answer to questions like –

• What is ChronoMeter?
• Why should we consider ChronoMeter while designing ui for any app?
• What are possibilities using ChronoMeter while designing ui? etc.

Let’s have a quick demo of things we want to cover in this tutorial –

Output

Tutorialwing Kotlin ChronoMeter Output

Tutorialwing Kotlin ChronoMeter Output

Getting Started

We can define android ChronoMeter widget as below –

ChronoMeter is simple widget that can be used as simple timer. You can count up or down with a given base time using chronoMeter. If you do not provide a base time, it will assume base time as time at which you call start() method.

Now, how do we use ChronoMeter in android application ?

Creating New Project

At first, we will create an application.
So, follow steps below to create any android project in Kotlin –

Step	Description
1.	Open Android Studio (Ignore if already done).
2.	Go to File => New => New Project. This will open a new window. Then, under Phone and Tablet section, select Empty Activity. Then, click Next.
3.	In next screen, select project name as ChronoMeter. Then, fill other required details.
4.	Then, clicking on Finish button creates new project.

Some very important concepts (Recommended to learn before you move ahead)

Before we move ahead, we need to setup for viewBinding to access Android ChronoMeter Using Kotlin file without using findViewById() method.

Setup ViewBinding

Add viewBinding true in app/build.gradle file.

Now, set content in activity using view binding.
Open MainActivity.kt file and write below code in it.

Now, we can access view in Kotlin file without using findViewById() method.

Using ChronoMeter in Kotlin

Follow steps below to use ChronoMeter in newly created project –

• Open res/values/strings.xml file. Then, add below code into it.
• Open res/layout/activity_main.xml file. Then, add below code in it –
• We can also access it in Kotlin File, MainActivity.kt, as below –

We have accessed button and chronoMeter using kotlin file (i.e. MainActivity.kt file) in the application. Then, we have set a click listener to play/pause chronoMeter. We are also showing message, as toast message, that represents the current status of the chronoMeter.

Now, run the application. We will get output as below –

Tutorialwing Kotlin ChronoMeter Output

Tutorialwing Kotlin ChronoMeter Output

Different Attributes of ChronoMeter in XML

Now, we will see how to use different attributes of Android ChronoMeter using Kotlin to customise it –

Set Id of ChronoMeter

Many a time, we need id of View to access it in kotlin file or create ui relative to that view in xml file. So, we can set id of ChronoMeter using android:id attribute like below –

Here, we have set id of ChronoMeter as chronoMeter_ID using android:id=”” attribute. So, if we need to reference this ChronoMeter, we need to use this id – chronoMeter_ID.
Learn to Set ID of ChronoMeter Dynamically

Set Width of ChronoMeter

We use android:layout_width=”” attribute to set width of ChronoMeter.
We can do it as below –

Width can be either “MATCH_PARENT” or “WRAP_CONTENT” or any fixed value (like 20dp, 30dp etc.).
Learn to Set Width of ChronoMeter Dynamically

Set Height of ChronoMeter

We use android:layout_height=”” attribute to set height of ChronoMeter.
We can do it as below –

Height can be either “MATCH_PARENT” or “WRAP_CONTENT” or any fixed value.
Learn to Set Height of ChronoMeter Dynamically

Set Padding of ChronoMeter

We use android:padding=”” attribute to set padding of ChronoMeter.
We can do it as below –

Here, we have set padding of 10dp in ChronoMeter using android:padding=”” attribute.
Learn to Set Padding of ChronoMeter Dynamically

Set Margin of ChronoMeter

We use android:layout_margin=”” attribute to set margin of ChronoMeter.
We can do it as below –

Here, we have set margin of 10dp in ChronoMeter using android:layout_margin=”” attribute.
Learn to Set Margin of ChronoMeter Dynamically

Set Background of ChronoMeter

We use android:background=”” attribute to set background of ChronoMeter.
We can do it as below –

Here, we have set background of color #ff0000 in ChronoMeter using android:background=”” attribute.
Learn to Set Background of ChronoMeter Dynamically

Set Visibility of ChronoMeter

We use android:visibility=”” attribute to set visibility of ChronoMeter.
We can do it as below –

Here, we have set visibility of ChronoMeter using android:visiblity=”” attribute. Visibility can be of three types – gone, visible and invisible
Learn to Set Visibility of ChronoMeter Dynamically

Set Text of ChronoMeter

We use android:text=”” attribute to set text of ChronoMeter.
We can do it as below –

Here, we have set text (“Hello Tutorialwing”) in ChronoMeter using android:text=”” attribute.
Similarly, we can set any text using this attribute.
Learn to Set Text of ChronoMeter Dynamically

Set Color of Text in ChronoMeter

We use android:textColor=”” attribute to set color of text in ChronoMeter.
We can do it as below –

Here, we have set color (#ffffff i.e. white) of text (“Hello Tutorialwing”) in ChronoMeter using android:textColor=”” attribute. Similarly, we can set any color using this attribute.
Learn to Set Color of ChronoMeter Dynamically

Set Gravity of ChronoMeter

We use android:gravity=”” attribute to set gravity of text in ChronoMeter.
We can do it as below –

Here, we have set gravity of text in ChronoMeter using android:gravity=”” attribute. Attribute value can be – “center_horizontal”, “center”, “center_vertical” etc.
Learn to Set Gravity of ChronoMeter Dynamically

Set Text in Uppercase, Lowercase

If we need to show text of ChronoMeter in uppercase or lowercase etc.

Set text in uppercase

We can use android:textAllCaps=”true” attribute to set text in uppercase. We can do it as below –

Attribute android:textAllCaps=”true” sets text in uppercase. So, HELLO TUTORIALWING is set in ChronoMeter.

By default, false is set in this attribute. So, Whatever value is written in android:text=”” attribute, it will be set as it is. For example,

Above code will set Hello Tutorialwing to ChronoMeter.

How do we set text in lowercase?

• In xml file – write all the text in lowercase.
• In kotlin file – take text as string. Then, convert it in lowercase. Then, set it to ChronoMeter.

Set Size of Text in ChronoMeter

We use android:textSize=”” attribute to set size of text in ChronoMeter.
We can do it as below –

Here, we have set size of text in ChronoMeter using android:textSize=”” attribute.
Learn to Set Size of Text of ChronoMeter Dynamically

Set Style (Bold/italic) of Text in ChronoMeter

We use android:textStyle=”” attribute to set style (bold, italic etc.) of text in ChronoMeter.
We can do it as below –

Here, we have set style of text in ChronoMeter using android:textStyle=”” attribute. This attribute can take bold, italic or normal.
Learn to Set Style of Text of ChronoMeter Dynamically

Set Letter Spacing of Text in ChronoMeter

We use android:letterSpacing=”” attribute to set spacing between letters of text in ChronoMeter.
We can do it as below –

Here, we have set spacing between letters of text in ChronoMeter using android:letterSpacing=”” attribute.
Learn to Set Letter Spacing of Text of ChronoMeter Dynamically

Set Typeface of Text in ChronoMeter

We use android:typeface=”” attribute to set typeface in ChronoMeter.
We can do it as below –

Here, we have set typeface of text in ChronoMeter using android:typeface=”” attribute. This attribute can take values – “sans”, “normal”, “monospace” or “normal”.
Learn to Set Typeface of ChronoMeter Dynamically

Set fontFamily of Text in ChronoMeter

We use android:fontFamily=”” attribute to set fontFamily of text in ChronoMeter.
We can do it as below –

Here, we have set fontFamily (Here, sans-serif) of text in ChronoMeter using android:fontFamily=”sans-serif” attribute.

Till now, we have see how to use android ChronoMeter using Kotlin. We have also gone through different attributes of ChronoMeter to perform certain task. Let’s have a look at list of such attributes and it’s related task.

Different Attributes of Android ChronoMeter Widget

Below are the various attributes that are used to customise android ChronoMeter Widget. However, you can check the complete list of attributes of ChronoMeter in it’s official documentation site. Here, we are going to list some of the important attributes of this widget –

Some of the popular attributes of android ChronoMeter widget are –

Sr.	XML Attributes	Description
1	android:countDown	Defines whether this chronometer will count up or count down from the base value
2	android:format	Defines the format of the string to be shown

Some of the popular attributes of android chronoMeter inherited from TextView are –

Sr.	XML Attributes	Description
1	android:gravity	Defines gravity of the view
2	android:height	Defines height of the view
3	android:maxHeight	Defines maximum height of the view
4	android:maxLength	Set an input filter to constrain the text length to the specified number
5	android:maxWidth	Defines maximum width of the view
6	android:minHeight	Defines minimum height of the view
7	android:minWidth	Defines minimum width of the view
8	android:width	Defines width of the view

Some of the popular attributes of android chronoMeter inherited from View are –

Sr.	XML Attributes	Description
1	android:alpha	Defines alpha of the view
2	android:background	Defines drawable of the background of the view
3	android:elevation	Defines elevation of the view
4	android:id	Defines id of the view
5	android:padding	Defines padding to apply the edges of the view
6	android:visibility	Defines visibility(VISIBLE, INVISIBLE or GONE) of the view

We have seen different attributes of ChronoMeter and how to use it. If you wish to visit post to learn more about it

Thus, we have seen what is ChronoMeter, how can we use android ChronoMeter using Kotlin ? etc. We also went through different attributes of android ChronoMeter.

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