Android SharedPreferences | Save Key-Value Example in Kotlin

Android SharedPreferences is store key-value (String, Integer, Boolean, etc) Paris data. SharedPreferences object points to a file holding a key-value pairs and provides simple methods to read and write data. It can be private or shared.

Android SharedPreferences Tutorial - Save Key Value data example in kotlin

SharedPreferences usually use for save a setting preference (push notification, alert, the default setting of the app, etc) or manage a login session in the app.

In this tutorial, you will learn following:

What is Android SharedPreferences and how to create it.
Saving and Retrieving data in SharedPreferences in Kotlin.

Create Shared Preferences

For a creating or accessing an existing shared preference, you can use by calling one of a method:

getSharedPreferences() – this method use for multiple shared preference files and it can identified by name. For call this have to use any Context of your app.
getPreferences() – Retrieve a default shared preferences file form the Activity (belong the activity).Its use only one shared preference file for the activity.

getSharedPreferences()

When naming your shared preference files, you should use a name that’s uniquely identifiable to your app. An easy way to do this is prefix the file name with your application ID. For example: "com.example.myapp.PREFERENCE_FILE_KEY"

val sharedPref = activity?.getSharedPreferences(
        getString(R.string.preference_file_key), Context.MODE_PRIVATE)

1 2	val sharedPref = activity?.getSharedPreferences( getString(R.string.preference_file_key), Context.MODE_PRIVATE)

getPreferences()

if you need just one shared preference file for your activity.

val sharedPref = activity?.getPreferences(Context.MODE_PRIVATE)

1	val sharedPref = activity?.getPreferences(Context.MODE_PRIVATE)

Note: The MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE modes have been deprecated since API level 17.

Write to shared preferences

You have call edit() on yourSharedPreferences, To write to a shared preferences file.

val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return
        with(sharedPref.edit()) {
            putString("name", et_name.text.toString())
            commit()
        }

val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return

with(sharedPref.edit()) {

putString("name", et_name.text.toString())

commit()

}

Pass the keys and values you want to write with methods for example : putInt() and putString(). Then call apply() orcommit() to save the changes. For example:

Check this tutorial question number #2 : What is the difference between commit() and apply() method in SharedPreferences()?

Read from shared preferences

val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return
        val str_name = sharedPref.getString("name", "")

1 2	val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return val str_name = sharedPref.getString("name", "")

To retrieve values from a shared preferences file, call methods getInt() and getString() etc, providing the key for the value you want, and optionally a default value to return if the key isn’t present. For example:

Let’s Build a Simple Example of Android SharedPreferences :

Step 1. Create new project “Build Your First Android App in Kotlin“

Step 2. Add following code in “activity_main.xml” layout file

adding 2 TextView and 2 Button. Where button have method to perform a Click action.

<?xml version="1.0" encoding="utf-8"?>
<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:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:text="Enter Details"
        android:textSize="16dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/et_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="8dp"
        android:ems="10"
        android:inputType="textPersonName"
        android:hint="Name"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView" />

    <EditText
        android:id="@+id/et_number"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="8dp"
        android:ems="10"
        android:hint="Number"
        android:inputType="phone"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/et_name" />

    <Button
        android:id="@+id/btn_save"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="32dp"
        android:text="Save"
        android:onClick="saveData"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/et_number" />

    <Button
        android:id="@+id/btn_get"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="32dp"
        android:text="Get"
        android:onClick="getData"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/et_number" />

</android.support.constraint.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>

<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:id="@+id/textView"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginTop="16dp"

android:text="Enter Details"

android:textSize="16dp"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent" />

<EditText

android:id="@+id/et_name"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="8dp"

android:ems="10"

android:inputType="textPersonName"

android:hint="Name"

app:layout_constraintEnd_toEndOf="parent"

app:layout_constraintStart_toStartOf="parent"

app:layout_constraintTop_toBottomOf="@+id/textView" />

<EditText

android:id="@+id/et_number"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="8dp"

android:ems="10"

android:hint="Number"

android:inputType="phone"

app:layout_constraintEnd_toEndOf="parent"

app:layout_constraintStart_toStartOf="parent"

app:layout_constraintTop_toBottomOf="@+id/et_name" />

<Button

android:id="@+id/btn_save"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginLeft="8dp"

android:layout_marginStart="8dp"

android:layout_marginTop="32dp"

android:text="Save"

android:onClick="saveData"

app:layout_constraintStart_toStartOf="parent"

app:layout_constraintTop_toBottomOf="@+id/et_number" />

<Button

android:id="@+id/btn_get"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginEnd="8dp"

android:layout_marginRight="8dp"

android:layout_marginTop="32dp"

android:text="Get"

android:onClick="getData"

app:layout_constraintEnd_toEndOf="parent"

app:layout_constraintTop_toBottomOf="@+id/et_number" />

</android.support.constraint.ConstraintLayout>

Step 3. Open the “MainActivity.kt” and add following code

In this code doing action by clicking button. Saving and getting data with same key.

package `in`.eyehunt.sharedpreferences

import android.content.Context
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

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

    //saving data
    fun saveData(view: View) {
        val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return
        with(sharedPref.edit()) {
            putString("name", et_name.text.toString())
            putInt("number", et_number.text.toString().toInt())
            commit()
        }
    }

    fun getData(view: View) {
        val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return
        val str_name = sharedPref.getString("name", "")
        val int_number = sharedPref.getInt("number", 0)
        Toast.makeText(this, "$str_name $int_number", Toast.LENGTH_LONG).show()

    }
}

package `in`.eyehunt.sharedpreferences

import android.content.Context

import android.support.v7.app.AppCompatActivity

import android.os.Bundle

import android.view.View

import android.widget.Toast

import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

setContentView(R.layout.activity_main)

}

//saving data

fun saveData(view: View) {

val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return

with(sharedPref.edit()) {

putString("name", et_name.text.toString())

putInt("number", et_number.text.toString().toInt())

commit()

}

fun getData(view: View) {

val sharedPref = this.getPreferences(Context.MODE_PRIVATE) ?: return

val str_name = sharedPref.getString("name", "")

val int_number = sharedPref.getInt("number", 0)

Toast.makeText(this, "$str_name $int_number", Toast.LENGTH_LONG).show()

}

Step 4. Now Run the application, in emulator or On you android device

Output screenshot Android SharedPreferences example :

Android SharedPreferences Tutorial - Save Key Value data example in kotlin output

Download source code Android SharedPreferences in kotlin

https://github.com/EyeHunts/SharedPreferences

Note: This example (Project) is developed in Android Studio 3.1.3. Tested on Android 9 ( Android-P), compile SDK version API 27: Android 8.0 (Oreo)
MinSdkVersion=”15″
TargetSdkVersion=”27″
Coding in Kotlin

Rohit

Degree in Computer Science and Engineer: App Developer and has multiple Programming languages experience. Enthusiasm for technology & like learning technical.

Android SharedPreferences – Save Key Value data example in kotlin

In this tutorial, you will learn following:

Create Shared Preferences

getSharedPreferences()

getPreferences()

Write to shared preferences

Read from shared preferences

Let’s Build a Simple Example of Android SharedPreferences :

Step 1. Create new project “Build Your First Android App in Kotlin“

Step 2. Add following code in “activity_main.xml” layout file

Step 3. Open the “MainActivity.kt” and add following code

Step 4. Now Run the application, in emulator or On you android device

Output screenshot Android SharedPreferences example :

Download source code Android SharedPreferences in kotlin

Related

Leave a Reply Cancel reply

In this tutorial, you will learn following:

Create Shared Preferences

getSharedPreferences()

getPreferences()

Write to shared preferences

Read from shared preferences

Let’s Build a Simple Example of Android SharedPreferences :

Step 1. Create new project “Build Your First Android App in Kotlin“

Step 2. Add following code in “activity_main.xml” layout file

Step 3. Open the “MainActivity.kt” and add following code

Step 4. Now Run the application, in emulator or On you android device

Output screenshot Android SharedPreferences example :

Download source code Android SharedPreferences in kotlin

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Leave a Reply Cancel reply