[JAVA] Is it an Android app?

Finally Christmas Eve, I was waiting for this day. Can he have a happy night trying to make her by Christmas using her agile?… A certain company's Advent calendar

Works Human Intelligence Advent Calendar 2020 that embodies "Develop fun!" Works Human Intelligence # 2 Advent Calendar 2020 that embodies "Develop fun!"

But don't worry [^ 1] I did my best this month and wrote various things. And I had a lot of people reading this article, this article, this article, and it was a lot of fun to hear their impressions. .. Is it an Advent calendar? Advent Calendar 2020 has received a total of 304 LGTM. By the way, how many people read this article this article, which was the source of my calendar name? image.png No, I'm not saying it's a small number (thanks to everyone who read it). But see below image.png The number of LGTM is only one. Why are everyone so scared of identifying the company name, or do they not want to step on the fumi-e? If you answered Yes, please come back immediately with your browser back. [^ 2]

If you can say that you can do this today, the range of new jobs will expand . I usually work with gorigori business apps (and the main battlefield is the back end), but sometimes I also want to make a stylish and heartful consumer app. Yes, it's an Android app![^ 3] Batch Job I wanted to review the basics of making a cute guy that can be enjoyed and used in the palm of my hand, which I may not be able to make for a lifetime.

It is Most Breakthrough App to make.

I'm ready

Android Studio Create an Android project using Android Stuidio It seems that the specs should be as follows.

RAM 3GB or more, recommended 8GB or more, + 1GB when using emulator Free disk space of 2GB or more, recommended 4GB or more Screen resolution 1280 x 800 or higher

MostBreakthroughApplication I gave it a name. The activity you select here should be very simple at first. Please note that the image below is selected as Bottom Navigation Activity. image.png

Reference: Select "Empty Activity" which is easy to use because it is the first. (It's easy to think of it as Basic ... but it's not simple and it's difficult to use at first, so don't make a mistake.) The word HAXM appears on the screen, and I wonder what this is, but problem-solving is the job, so you can proceed while working. The emulator etc. starts up.

Hello World

For the time being, it will be as follows. image.png

Perform Emulator Settings based on Hello World! App Creation, and then execute. Please be aware that this Virtual Device also squeezes the disk with a few GB. Is Hello World displayed successfully on the emulator? image.png

Do you want to put the button?

I haven't coded anything, but I'll make it work without worrying about it. The display changes with onClick.


    protected void onCreate(Bundle savedInstanceState) {

        //Set button
        Button breakthrough = findViewById(R.id.button);
        editTexttop = findViewById(R.id.editTextTextMultiLineTop);
        editTextbottom = findViewById(R.id.editTextTextMultiLineBottom);
        breakthrough.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                // ...
                    editTextbottom.setText("There is");
                    buttonTap= false;
                    buttonTap= true;

I just encountered Android Studio doesn't auto-complete ConstraintLayout and gives an error, but it's resolved below. Android's new Layout, ConstraintLayout Beginning What is ConstraintLayout?

ConstraintLayout automatically adjusts the layout position to the optimum position according to the material design.

I'll commit to the following while troubleshooting. https://github.com/e99h2121/MostBreakthroughApp/blob/main/app/src/main/java/com/example/mostbreakthroughapp/MainActivity.java

arimasumaika.gif Make sure you've successfully broken through. image.png Character color etc. can be changed by changing the property on the xml side.

It's an operation check

At this point, the usual Are you sure replacement will work?

Expected behavior




It's overwhelmingly easy for you guys who are already familiar with critical tasks, but if you want to publish your app, take a look at this page: Publish App If you haven't released it, you need to register as a developer on the Play Store $ 25 is an easy cost to solve the problem. Google Play Console


What is a real job? It starts when you face a big problem

Ho Ho Ho ... Isn't there even an in-house Slack bot energizing before I knew it? image.png

What was obtained

While thinking that nothing might be interesting if you can't share the original story so far, Android application creation itself is always within reach, and for those of you who are critical of the usual fun development work. I came to realize that there is no doubt that I can recommend it.

Not only Java but also Kotlin will be the main subject, so it's a great subject to hone your breakthrough creativity. Of course, the Hello world-like process can be done according to this article, so if you haven't done it, please try it! In the near future, I wanted to make something that would be seriously played by the little ones for myself so that I would love bonsai.


Have a nice Christmas. Tomorrow I will summarize the Advent calendar.

[^ 1]: A story about introducing CI in a desolate development environment in the first year of a new graduate and propagating unit tests, of course, but I can't touch it here because it smears his article. ..

[^ 2]: See Think about how to make her by Christmas with Agile.

[^ 3]: Compared to Taco rice over time, concentration reduction is undeniable. Please forgive me because I made a mistake when I started writing the article.

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