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

Cal Song
Cal Song
13,934 Points

I have no clue how to solve this.. Lastly, retrieve the saved value in onCreate and set the state of the CheckBox. If t

Like I mentioned in the title, I have no idea how to solve this.

If anybody could explain it to me, i'd really appreciate it.

Thanks!

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

public class MainActivity extends Activity {

  private SharedPreferences mSharedPreferences;
  private SharedPreferences.Editor mEditor;

  private static final String PREFS_FILE = "PREFS_FILE";
  private static final String KEY_CHECKBOX = "KEY_CHECKBOX";

  public CheckBox mCheckBox;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mSharedPreferences = getSharedPreferences(PREFS_FILE, Context.MODE_PRIVATE);
    mEditor = mSharedPreferences.edit();
    mCheckBox = (CheckBox) findViewById(R.id.checkBox);
    Boolean mIsChecked = mSharedPreferences.getBoolean(KEY_CHECKBOX, false);
    mCheckBox.setChecked(mIsChecked);
  }


  @Override
  protected void onPause() {
    super.onPause();
    mEditor.putBoolean(KEY_CHECKBOX, mCheckBox.isChecked());
    mEditor.apply();
  }
}

2 Answers

Kourosh Raeen
Kourosh Raeen
23,732 Points

I just tried the code you've written and it passed the challenge. The way I had written the code for the last task was like this:

mCheckBox.setChecked(mSharedPreferences.getBoolean(KEY_CHECKBOX, false));

But As I said the way you wrote it works too.

Sai Iyengar
Sai Iyengar
7,155 Points

I think you need to initialize the checkBox findViewById() before defining the SharedPreferences.

Kourosh Raeen
Kourosh Raeen
23,732 Points

That order doesn't really matter as long as they are defined before you start using them.