Android SharedPreferences using Kotlin

Pandiyan Mani

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Mar 26, 2023

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Shared Preferences is the way in which one can store and retrieve small amounts of primitive data as key/value pairs to a file on the device storage such as String, int, float, Boolean that make up your preferences in an XML file inside the app on the device storage

SharedPreferences Setting/Retrieving Values using Kotlin

val sharedPreference =  getSharedPreferences("PREFERENCE_NAME",Context.MODE_PRIVATE)
var editor = sharedPreference.edit()
editor.putString("username","Anupam")
editor.putLong("l",100L)
editor.commit()

For retrieving a value:

sharedPreference.getString("username","defaultName")
sharedPreference.getLong("l",1L)

The permitted types on a SharedPreference instance are:

Kotlin Code to Clear and Remove SharedPreferences Records

We can also clear all the values or remove a particular value by calling clear() and remove(String key) methods.

editor.clear()
editor.remove("username")

Lets Jump in to the Coding Part where we store UserName and Display UserName.

So i am create an xml for getting UserName from User so inside activity_main.xml i added the EditText View along with that we have a TextView for Displaying saved UserName and Three Button one is for save, clear and Display Username..

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/editusername"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter UserName"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    
    <TextView
        android:id="@+id/username"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/black"
        android:text="Currently UserName is Empty"
        >
        
    </TextView>
    
    <Button
        android:id="@+id/save"
        android:text="SAVE"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        
    </Button>

    <Button
        android:id="@+id/clear"
        android:text="CLEAR"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </Button>

    <Button
        android:id="@+id/display"
        android:text="DISPLAY USERNAME"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </Button>

</LinearLayout>

And let see the complete code of MainActivity.kt

package com.student.sharedpreferencce

import android.content.Context
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import android.widget.TextView

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val sharedPreference =  getSharedPreferences("PREFERENCE_NAME", Context.MODE_PRIVATE)
        var editor = sharedPreference.edit()

        val save = findViewById<Button>(R.id.save)
        val clear = findViewById<Button>(R.id.clear)
        val display = findViewById<Button>(R.id.display)
        val editusername = findViewById<EditText>(R.id.editusername)
        val username = findViewById<TextView>(R.id.username)

        username.text = sharedPreference.getString("username","")

        save.setOnClickListener {
            if(editusername.text.isNotEmpty()) {
                editor.putString("username",editusername.text.toString())
                editor.commit()
            }
        }

        clear.setOnClickListener {
            editor.clear()
            editor.remove("ausername")
            editor.apply()
        }

        display.setOnClickListener {
            username.text = sharedPreference.getString("username","")
        }
    }
}

And above code are straight forward as we don't need any separate explanation Thanks Happy Coding.

Final Output: