SharedPreferences | Android Studio | Kotlin
SharedPreferences is one of the types of saving data in Android Devices. You can save String, int, boolean, long, float, and Set<String> types of data in SharedPreferences. In SharedPreferences data is saved in the key-value form. If you have a relatively small collection of key-values that you’d like to save, then you should use the SharedPreferences APIs. You can Add, Edit/Modify and Remove data from the SharedPreferences easily.
To get the access to the preferences, we have the three APIs to choose from:
getPreferences() : used from within your Activity, to access the activity-specific preferences.
getSharedPreferences() : used from within your Activity (or other application Context), to access the application-level preferences.
getDefaultSharedPreferences() : used on the PreferenceManager, to get the shared preferences that work in concert with Android’s overall preference framework.
Step 1: Create a new project or open an existing project
Step 2: Code
activity_main.xml
<?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"
android:padding="10dp"
tools:context=".MainActivity">
<EditText
android:id="@+id/nameEt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Name"
android:inputType="textPersonName|textCapWords" />
<EditText
android:id="@+id/ageEt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Age"
android:inputType="date" />
<EditText
android:id="@+id/emailEt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Email"
android:inputType="textEmailAddress" />
<EditText
android:id="@+id/passwordEt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Password"
android:inputType="textPassword" />
<CheckBox
android:id="@+id/rememberCb"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Remember" />
<Button
android:id="@+id/saveBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:text="Save" />
</LinearLayout>
MainActivity.kt
package com.jigopost.myapplication
import android.content.Context
import android.content.SharedPreferences
import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.CheckBox
import android.widget.EditText
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*
class MainActivity : AppCompatActivity() {
//variables
var name: String? = null
var email: String? = null
var password: String? = null
var age = 0
var isRemembered = false
//shared pref
lateinit var sharedPreferences: SharedPreferences
lateinit var spEditor: SharedPreferences.Editor
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
//init share pref
sharedPreferences = getSharedPreferences("USER_INFO_SP", Context.MODE_PRIVATE)
//get data from shared preferences
name = sharedPreferences.getString("NAME", "")
age = sharedPreferences.getInt("AGE", 0)
email = sharedPreferences.getString("EMAIL", "")
password = sharedPreferences.getString("PASSWORD", "")
isRemembered = sharedPreferences.getBoolean("REMEMBER", false)
//set data to views
nameEt.setText(name)
ageEt.setText("" + age)
emailEt.setText(email)
passwordEt.setText(password)
rememberCb.setChecked(isRemembered)
//click to input data from views
saveBtn.setOnClickListener(View.OnClickListener {
//get data from views
name = "" + nameEt.getText().toString().trim()
age = ageEt.getText().toString().trim().toInt()
email = "" + emailEt.getText().toString().trim()
password = "" + passwordEt.getText().toString().trim()
if (rememberCb.isChecked()) {
isRemembered = true
//save data to shared preferences
spEditor = sharedPreferences.edit()
spEditor.putString("NAME", name)
spEditor.putInt("AGE", age)
spEditor.putString("EMAIL", email)
spEditor.putString("PASSWORD", password)
spEditor.putBoolean("REMEMBER", true)
spEditor.apply()
Toast.makeText(this@MainActivity, "Info is remembered...", Toast.LENGTH_SHORT).show()
} else {
isRemembered = false
//don't save | remove data from shared preferences
spEditor = sharedPreferences.edit()
spEditor.clear()
spEditor.apply()
Toast.makeText(this@MainActivity, "Info is not remembered...", Toast.LENGTH_SHORT).show()
}
})
}
}
Step 3: Run Project
Output
