Implement Shared Preferences In Android Applications

Introduction

Android is one of the most popular operating systems for mobile. Shared preference has the responsibility for framework or file can be private or shared and, it stores the key value set. So, I will show you how to implement shared preference in your Android application using Android studio. Android is a kernel based operating system. It allows the user to modify the GUI components and source code.

Requirements

• Android studio
• Little bit XML and JAVA Knowledge.
• Android emulator (or) android mobile
• Download link (android studio)

Steps should be followed

Carefully follow my steps to implement shared preference in your Android application using Android studio and I have  included the source code below.

Step 1

Open Android studio start the new project.



Step 2

Put the application name and company domain. If you wish to use c++ for coding the project , mark the Included c++ support then click next.



Step 3

Select the Android minimum SDK. After you choose the minimum SDK it will show the approximate percentage of people using that sdk then click next.



Step 4

Choose the basic activity then click next.



Step 5

Put the activity name and layout name. Android studio basically takes the java class name as what you provide for the activity name and click finish.



Step 6

Go to activity_main.xml then click the text bottom. This xml file contains the designing code for android apps. Into the activity_main.xml copy and paste the below code.

Activity_main.xml code

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="@string/user_name"
        android:id="@+id/textView"
        tools:ignore="RtlHardcoded"
        tools:layout_constraintTop_creator="1"
        android:layout_marginStart="16dp"
        android:layout_marginTop="62dp"
        tools:layout_constraintLeft_creator="1"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="@string/password"
        android:id="@+id/textView2"
        tools:ignore="RtlHardcoded"
        tools:layout_constraintTop_creator="1"
        tools:layout_constraintBottom_creator="1"
        app:layout_constraintBottom_toTopOf="@+id/dataTextView"
        android:layout_marginStart="16dp"
        android:layout_marginTop="157dp"
        tools:layout_constraintLeft_creator="1"
        android:layout_marginBottom="157dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/passwordInput"
        android:width="200dp"
        tools:layout_constraintTop_creator="1"
        tools:layout_constraintRight_creator="1"
        app:layout_constraintRight_toRightOf="@+id/userNameInput"
        android:layout_marginTop="53dp"
        app:layout_constraintTop_toBottomOf="@+id/userNameInput"
        tools:layout_constraintLeft_creator="1"
        app:layout_constraintLeft_toLeftOf="@+id/userNameInput" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/userNameInput"
        android:width="200dp"
        tools:layout_constraintTop_creator="1"
        android:layout_marginStart="43dp"
        android:layout_marginTop="45dp"
        tools:layout_constraintLeft_creator="1"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toRightOf="@+id/textView" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Save Info"
        android:id="@+id/saveButton"
        android:onClick="saveData"
        tools:ignore="HardcodedText"
        tools:layout_constraintBottom_creator="1"
        android:layout_marginStart="16dp"
        app:layout_constraintBottom_toBottomOf="parent"
        tools:layout_constraintLeft_creator="1"
        android:layout_marginBottom="200dp"
        app:layout_constraintLeft_toLeftOf="parent" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/display_info"
        android:id="@+id/displayButton"
        android:onClick="getData"
        tools:layout_constraintTop_creator="1"
        tools:layout_constraintRight_creator="1"
        tools:layout_constraintBottom_creator="1"
        app:layout_constraintBottom_toBottomOf="@+id/saveButton"
        android:layout_marginEnd="1dp"
        app:layout_constraintRight_toRightOf="@+id/passwordInput"
        app:layout_constraintTop_toTopOf="@+id/saveButton" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:id="@+id/dataTextView"
        tools:layout_constraintTop_creator="1"
        android:layout_marginTop="61dp"
        app:layout_constraintTop_toBottomOf="@+id/displayButton"
        tools:layout_constraintLeft_creator="1"
        app:layout_constraintLeft_toLeftOf="@+id/displayButton" />

</android.support.constraint.ConstraintLayout>

 

User interface



Step 7

Into the MainActivity.java copy and paste the below code.java programming is the backend language for Android. Do not replace your package name otherwise the app will not run.

MainActivity.java code

package ganeshannt.sharedpref;

import android.content.Context;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {
    EditText userName;
    EditText password;
    TextView dataView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        userName = (EditText) findViewById(R.id.userNameInput);
        password = (EditText) findViewById(R.id.passwordInput);
        dataView = (TextView) findViewById(R.id.dataTextView);

    }
    // Lesson 64
    //Save login info
    public void saveData(View view){
        SharedPreferences loginData = getSharedPreferences("userInfo", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = loginData.edit();
        editor.putString("userName", userName.getText().toString());
        editor.putString("password", password.getText().toString());
        editor.apply();

        Toast.makeText(this,"Saved",Toast.LENGTH_LONG).show();
    }

    public void getData(View view){
        SharedPreferences loginData = getSharedPreferences("userInfo", Context.MODE_PRIVATE);
        String name = loginData.getString("userName", "");
        String pw = loginData.getString("password","");
        String msg = "Saved User Name: " + name + "\nSaved Password: " + pw;
        dataView.setText(msg);
    }
}

 

Step 8

Click the make project option and run.



Step 9

Run the application then choose the virtual machine then click ok.



Deliverables

Here we have  successfully implemented shared preference in the created and executed android app 

Type the username and password



Click save button



Click the displayinfo button then it will show the data because that time it saved username and data information was shared to that onclick method by the help of shared preference



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