This example demonstrates how to delete SharedPreferences data for my Android App using Kotlin.
Step 1 − Create a new project in Android Studio, go to File ? New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml.
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" xmlns:tools="https://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center_horizontal" android:orientation="vertical" android:padding="8dp" tools:context=".MainActivity"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="100dp" android:layout_marginBottom="100dp" android:textAlignment="center" android:textColor="@android:color/holo_green_dark" android:textSize="32sp" android:textStyle="bold" /> <TextView android:id="@+id/textView" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginBottom="20dp" android:textAlignment="center" android:textColor="@android:color/background_dark" android:textSize="20sp" android:textStyle="bold" /> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Delete Shared Preference" /> <TextView android:id="@+id/tvAfterChange" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:textAlignment="center" android:textColor="@android:color/holo_red_light" android:textSize="20sp" android:textStyle="bold" /> </LinearLayout>
Step 3 − Add the following code to src/MainActivity.kt
import android.content.Context import android.content.SharedPreferences import android.os.Bundle import android.widget.Button import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { lateinit var textView: TextView lateinit var tvAfterDelete: TextView lateinit var sharedPreferences: SharedPreferences lateinit var editor: SharedPreferences.Editor lateinit var button: Button override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) textView = findViewById(R.id.textView) tvAfterDelete = findViewById(R.id.tvAfterChange) button = findViewById(R.id.button) title = "KotlinApp" sharedPreferences = getPreferences(Context.MODE_PRIVATE) editor = sharedPreferences.edit() editor.putString(resources.getString(R.string.sharedPref_key_player), "Cristiano Ronaldo") editor.putString(resources.getString(R.string.sharedPref_key_country), "Portugal") editor.apply() val player = sharedPreferences.getString(resources.getString(R.string.sharedPref_key_player), "") val country = sharedPreferences.getString(resources.getString(R.string.sharedPref_key_country), "") textView.text = "SharedPreferences Values\n" textView.text = "Player : $player\nCountry : $country" button.setOnClickListener { editor.remove(resources.getString(R.string.sharedPref_key_country)) editor.apply() val playerNow = sharedPreferences.getString(resources.getString(R.string.sharedPref_key_player), "") val countryNow = sharedPreferences.getString(resources.getString(R.string.sharedPref_key_country), "") tvAfterDelete.text = "SharedPreferences Values - After Removing City\n" tvAfterDelete.text = "Country : $playerNow\nCountry : $countryNow" } } }
Step 4 − Add the following code in res/values/string.xml
<string name="sharedPref_key_player">player_name</string> <string name="sharedPref_key_country">country_name</string>
Step 5 − Add the following code to androidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="https://schemas.android.com/apk/res/android" package="app.com.q10"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen