How do I delete SharedPreferences data for my Android App?

AndroidAppsMobile Development

This example demonstrates how do I delete SharedPreferences data for my android app.

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="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:gravity="center"
   android:orientation="vertical"
   android:padding="8dp"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/textView"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_marginBottom="20dp"
      android:textAlignment="center"
      android:textSize="20sp"
      android:textStyle="bold" />
   <Button
      android:id="@+id/button"
      android:layout_width="match_parent"
      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:textSize="20sp"
      android:textStyle="bold" />
</LinearLayout>

Step 3 − Add the following code to res/strings.xml

<resources>
   <string name="app_name">Sample</string>
   <string name="sharedPref_key_player">player_name</string>
   <string name="sharedPref_key_country">country_name</string>
</resources>

Step 4 − Add the following code to src/MainActivity.java

import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
   TextView textView, tvAfterDelete;
   SharedPreferences sharedPreferences;
   SharedPreferences.Editor editor;
   Button button;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      textView = findViewById(R.id.textView);
      tvAfterDelete = findViewById(R.id.tvAfterChange);
      button = findViewById(R.id.button);
      sharedPreferences = getPreferences(Context.MODE_PRIVATE);
      editor = sharedPreferences.edit();
      editor.putString(getResources().getString(R.string.sharedPref_key_player), "Cristiano Ronaldo");
      editor.putString(getResources().getString(R.string.sharedPref_key_count ry), "Portugal");
      editor.apply();
      String country = sharedPreferences.getString(getResources().getString(R.string.sharedPre f_key_player), "");
      String city = sharedPreferences.getString(getResources().getString(R.string.sharedPre f_key_country), "");
      textView.setText("SharedPreferences Values\n");
      textView.setText(textView.getText() + "Country : " + country + "\nCity : " + city);
      button.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View view) {
            editor.remove(getResources().getString(R.string.sharedPref_key_country));
            editor.apply();
            String countryNow = sharedPreferences.getString(getResources().getString(R.string.sharedPre f_key_player), "");
            String cityNow = sharedPreferences.getString(getResources().getString(R.string.sharedPre f_key_country), "");
            tvAfterDelete.setText("SharedPreferences Values - After Removing City\n");
            tvAfterDelete.setText(tvAfterDelete.getText() + "Country : " + countryNow + "\nCity : " + cityNow);
         }
      });
   }
}

Step 5 − Add the following code to androidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <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 the android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −

Click here to download the project code.

raja
Published on 21-Nov-2019 10:54:51
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