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Android Android Activity Lifecycle Introducing SharedPreferences Saving and Retrieving Data with SharedPreferences

Posted by Enrique Hernández
Enrique Hernández
2,822 Points

Got stuck on challenge 3 of 4 Android Activity Lifecycle

Override the onPause method. Then save the value of the CheckBox. Hint: Use isChecked() to get the value of the CheckBox, and use 'putBoolean' to store the value.

This is the code but i tried using the answers given and can't get this done.

import android.view.View; import android.os.Bundle;

public class MainActivity extends Activity {

public CheckBox mCheckBox; private static final String PREFS_FILE = "com.packagename.preferences"; private static final String KEY_CHECKBOX = "KEY_CHECKBOX"; private SharedPreferences.Editor mEditor; private SharedPreferences mSharedPreferences;

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);

mCheckBox = (CheckBox) findViewById(R.id.checkBox);

mSharedPreferences = getSharedPreferences(PREFS_FILE, Context.MODE_PRIVATE); mEditor=mSharedPreferences.edit();

} }

MainActivity.java 
import android.view.View;
import android.os.Bundle;

public class MainActivity extends Activity {

  public CheckBox mCheckBox;
private static final String PREFS_FILE = "com.packagename.preferences";
  private static final String KEY_CHECKBOX = "KEY_CHECKBOX";
   private SharedPreferences.Editor mEditor;
  private SharedPreferences mSharedPreferences;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mCheckBox = (CheckBox) findViewById(R.id.checkBox);
  mSharedPreferences = getSharedPreferences(PREFS_FILE, Context.MODE_PRIVATE);
        mEditor=mSharedPreferences.edit();



  }
}

2 Answers

Kourosh Raeen
Kourosh Raeen
23,733 Points
Kourosh Raeen
Kourosh Raeen
23,733 Points

In the onPause() method, call the putBoolean() method on the Editor instance mEditor. Pass in the key and the boolean value of the checkbox which you can get by calling isChecked() on mCheckBock. Finally, call apply() on the Editor instance.

import android.view.View;
import android.os.Bundle;

public class MainActivity extends Activity {

  private static final String PREFS_FILE = "com.packagename.preferences";
  private static final String KEY_CHECKBOX = "KEY_CHECKBOX";

  public CheckBox mCheckBox;
  private SharedPreferences.Editor mEditor;
  private SharedPreferences mSharedPreferences;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mCheckBox = (CheckBox) findViewById(R.id.checkBox);
    mSharedPreferences = getSharedPreferences(PREFS_FILE, Context.MODE_PRIVATE);
    mEditor = mSharedPreferences.edit();
  }

  @Override
  protected void onPause() {
    super.onPause();
    mEditor.putBoolean(KEY_CHECKBOX, mCheckBox.isChecked());
    mEditor.apply();
  }
}
Enrique Hernández
Enrique Hernández
2,822 Points
Enrique Hernández
Enrique Hernández
2,822 Points

Thank you, it worked!