Android studio регистрация пользователя

В этом уроке мы продолжим увеличивать свои способности в настройке пользовательского интерфейса своих приложений и оборудовать их все более серьезными вещами. На этот раз мы оснастим свое Android приложение функцией входа в приложение по вводу логина и пароля. Это может пригодится для многих приложений, да и просто интересно, как это делается. Все довольно просто, ничего сложного в реализации этой возможности не будет.

Мы сделаем приложение, при запуске которого нужно будет выполнить вход с помощью ввода логина и пароля — если данные введены верно мы попадаем на другой экран, если не правильно, то видим сообщение об ошибке.

Здесь пригодится вспомнить простенький урок о переходе между двумя экранами, этот прием встречался уже неоднократно, поэтому разъяснений по нему делать уже не буду.

Создаем новый проект, выбираем Blank Activity. Для начала создадим пользовательский интерфейс для приложения. Он будет состоять из полей ввода логина/пароля и кнопки для совершения входа. Открываем файл activity_main.xml и добавляем туда следующее:

Мы получили вот такой вид пользовательского интерфейса:

Сразу разберемся со вторым экраном, на который будет совершаться переход в случае успешного ввода логина и пароля. Создаем новый класс по имени Second.java:

И соответствующий ему layout файл по имени second_activity.xml:

Ну а теперь переходим к файлу основному MainActivity.java. Основной процесс будет происходить в методе обработки нажатия кнопки «Войти». В нем мы сравниваем введенные логин и пароль со словом admin и в зависимости от их совпадения или не совпадения настраиваем дальнейшие действия. Если введены логин и пароль admin, то высвечивается Toast сообщение об успехе входа и выполняется переход на второй экран с помощью Intent. Если данные введены не верно, то высвечивается сообщение с ошибкой, а после 3 неудачных попыток появляется надпись, что количество попыток исчерпано, а кнопка «Войти» становится неактивной. Итак, чтобы реализовать сказанное, открываем файл MainActivity.java и добавляем в него следующий код:

Кстати, не забудьте добавить вторую activity в файл манифеста AndroidManifest.xml:

Проверяем работоспособность своего творения:

Вот так, все отлично работает, теперь мы можем сделать свое приложение насколько крутым, что им смогут пользоваться только знающие данные логина и пароля для входа.

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ok, this is my first article in Medium. In this section, I want to share with you about the User Interface on Android and we will create a Login page and a Register page. Some components that I will use:
1. Viewpager
2. Fragment
3. Edittext
4. Button
5. Textview
6. Imageview

What about the results? let’s coding (follow step by step)

Of course we must already have an Android Studio. if not, you can download it first on the official Android Studio website. If you already have one, please open your Android studio.

2. We create a new project by clicking “Start a new Android Studio project”. Fill in the application name column with “LoginApp”, then click next.

3. Select the minimum SDK you need or want, then click next.

4. Select “Empty Activity” and click next. After that, the “Activity Name” and “Layout Name” columns will appear, in this section just leave it like that, then click finish.

After you click finish, Android Studio will make you an Application with the name “LoginApp”.

After the application is successfully built, you can simply make adjustments to the following sections:

Open the colors.xml file in app/res/values/colors.xml, and change it like this:

Create a folder with the name “font” in the res folder, by right clicking on the res directory, select new / directory and name it “font”. After that, copy this font into font directory. (download the font 1 and font 2).

Create some Drawable Resource File in the drawable directory, by right-clicking on the drawable directory, select new / Drawable Resource File.

After that open file styles.xml and change like this :

Add the theme property in the Main Activity in the manifest, in the app / manifests / AndroidManifest.xml folder

So the AndroidManifest.xml file will be as follows:

After all the steps above are done, then make 2 fragments with the name fragment_login and fragment_register in the layout directory, by right-clicking on the layout directory, New/Fragment/Fragment (Blank)

Uncheck:
include fragment factory methods? and include interface methods?

Adjustment of several layouts :

change the activity_main.xml layout, fragment_login.xml and fragment_register.xml so that it will be as below

Open the strings.xml file in the res / values / strings.xml directory and change it to something like the following :

So that the overall structure of the project will be as follows :

Connect fragments with viewpager

Create an inner class in the MainActivity.java class with the name AuthenticationPapterAdapter. This class is a derivative of the FragmentPagerAdapter class and serves to connect Fragments with ViewPager,

Then call the class in the onCreate() method in MainActivity.java and connect with viewpager

So the MainActivity.java class will be like this

The display of the final application will be like this

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Operating System

In this tutorial, we will try to create a Simple Registration and Login Application using Android. This simple application can be used in any system that needed a login verification. Android is a mobile operating system developed by Google. It used in several gadgets like smartphones, tablets, and even television. Android is open source to developers who has an interest in developing mobile apps. It also provides an adaptive framework that allows the developer to develop an app in a simpler way. So let’s now do the coding.

Getting Started:

First, you will have to download & install the Android Development IDE (Android Studio or Eclipse). Android Studio is an open source development feel free to develop your things.

Layout Design

We will now create the design for the application, first locate the layout file called activity_main.xml, this is the default name when create a new activity. Then write these codes inside your layout file.

Android Manifest File

The Android Manifest file provides essential information about your app to the Android system in which the system must required before running the code. It describe the overall information about the application. It contains some libraries that needed to access the several method within the app.

Creating The Database

This code contain the script for creating a database and a database connection. To create this first create a new java file called DatabaseHelper, open the newly created file then extend the class by adding SQLiteOpenHelper. After that write these block of codes inside the DatabaseHelper class.

Creating the Registration

This code contains the register function of the application. This will insert the data to the database by calling the DatabaseHelper when the button is clicked. To do that just write these block of codes inside the MainActivity class.

This code contains the login function for the application. This code will read the entry field data then check the data if it exist in the DatabaseHelper class. To do that simply write these block of codes inside the Login class.

Try to run the app and see if it worked.

DEMO

There you have it we have created a Simple Registration and Login Application using Android. I hope that this tutorial help you to what you are looking for. For more updates and tutorials just kindly visit this site.

Enjoy Coding.

Note: Due to the size or complexity of this submission, the author has submitted it as a .zip file to shorten your download time. After downloading it, you will need a program like Winzip to decompress it.

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FOR YOUR OWN SAFETY, PLEASE:

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In software applications, it is mostly required to store users and app data locally. Android SDK provides several APIs for developers to save user and app data, So SQLite is one of the ways of storing data. For many applications, SQLite is the backbone of the app whether it’s used directly or via some third-party wrapper. In this tutorial, we will see how to use SQLite in our app directly.

What is SQLite?

SQLite is a lightweight database that comes with android. It is an Open-Source embedded SQL database engine. This provides a relational database management structure for storing user-defined records in the form of tables.

Key point to understand regarding SQLite :-

– SQLite is a RDBMS (Relational Database Management System)
– SQLite is written in C programming language
– SQLite is embedded within the Android operating system, so you don’t need anything external on Android to use SQLite
– To manipulate data (insert, update, delete) in SQLite database – we’ll use SQL (Structured Query Language)

Let’s Get it Working

In this tutorial we are going to learn how to use SQLite. To really understand the usage of SQLite we will create an app . The App contains simple Login form, Registration form and listing of registered user. This app shows how SQLite database operations are performed. I assume that you have created a new android project. Source Code is available on GitHub.

Step 1) Update build.gradle file.

Before you can use Material Design in your projects you need to add the following compile line to your Gradle dependencies block in your build.gradle file and rebuilt the project .

Step 2) Update strings.xml.

Add the below string values to the string.xml located in res => values => strings.xml.

Step 3) Update colors.xml.

Add the below color values to the colors.xml located in res => values => colors.xml.

Step 4) Update styles.xml.

Add the below style values to the styles.xml located in res => values => styles.xml.

Step 5) Add Logo Image.

Download the below logo image and add it to the drawable folder located in res => drawable.

Android Tutorials Hub Logo

Step 6) Create a User model class.

Create a new package named modal and create a User class with all getter and setter methods to maintain single contact as an object.

Step 7) Create a DatabaseHelper class.

Create a new package named SQL and create a DatabaseHelper class. Extend this class with SQLiteOpenHelper to manage database creation and version management. I have also written some methods to manipulate data in the database.

Methods and functionality

– addUser :- add a user to the database.
– getAllUser :- fetch users data from the database.
– updateUser :- update the user in the database on the basis of the user id.
– deleteUser :- delete user from the database on the basis of the user id.
– checkUser :- check whether the user exists in the database.

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User Table Schema

Step 8) Create activity_login.xml.

Now create a layout file for the LoginActivity.java i.e activity_login.xml and add the below code in your layout file. The code will create a simple login form containing logo on the top, 2 input fields email and password, login button, and registration screen navigation link.

activity_login.xml would result in a screen like this:

Step 8) Create InputValidation class.

Create a package named helpers and create a class in it named InputValidation.java and add below code in it. The code will create validation methods for the input field. Validation like empty input, valid email and etc.

Step 9) Create a LoginActivity class.

Now create a package named activities and create a class named LoginActivity and add below code. Here i have written the code to validate the input fields Email and Password using the InputValidation class which I described above. Also, code for navigation to registration screen on the click of registration link and to user list screen after clicking on the login button if credentials are valid.

The Screen below shows the login form with input validation display the error message if values entered in input fields are not valid.

The Screen below shows the login form with input validation display the snack bar with a message if values entered in input fields are not validated from the SQLite database.

Step 10) Create activity_register.xml.

Now create a layout file for the RegisterActivity.java i.e activity_register.xml and add the below code in your layout file. The code will create a simple registration form containing a logo on the top, 4 input fields name, email, password, and confirm password, register button, and login screen navigation link.

activity_register.xml would result in a screen like this:

Step 11) Create RegisterActivity class.

Now create a package named activities and create a class named RegisterActivity and add below code. Here I have written the code to validate the input fields Name, Email, Password, and Confirm Password using the InputValidation class which I described above. Also, code for navigation to the login screen on the click of login link and shows snackbar with success message for registration.

The Screen below shows the registration form with input validation display the error message if values entered in input fields are not valid.

The Screen below shows the filled registration form with valid values.

The Screen below shows the register form display the snackbar with the registration success message.

Step 12) Create activity_users_list.xml.

Now create a layout file for the UsersListActivity.java i.e activity_users_list.xml and add the below code in your layout file. The code will create a simple view containing two views one view i.e LinearLayout shows the welcome message with email id of the logged in user and another view i.e RecyclerView shows the list of registered users in the app.

activity_users_list.xml would result in a screen like this:

User List Screen

Step 13) Writing the Adapter Class.

Now create a package named adapters and create a class named UsersRecyclerAdapter and add below code. Here onCreateViewHolder() method inflates item_user_recycler.xml. In onBindViewHolder() method the appropriate User data (name, email, and password) set to each row.

item_user_recycler.xml

Step 14) Create UsersListActivity class.

Now create a package named activities and create a class named UsersListActivity and add below code. Here i have written the code to show the email id of the logged in user and the list of registered users.

The Screen below after user login shows the brand name, email id of logged in user, and registered users list.

User List Screen After Login

Step 15) Update AndroidManifest.xml.

To learn this tutorial using KOTLIN Language Click here.

Please feel free to comment as well as ask questions. And, yeah! If this post helps you please do share!

Enjoy Coding and Share Knowledge

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Android studio регистрация пользователя