Unable to save data in child activity android studio

Question

After entering the details in EditText in child activity when I go back to parent activity and comes back to child activity the EditText value is becoming blank. I have used below mentioned code, but no use.

Below mentioned is childactivity.java details.

Can anyone help in this.

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.TextView;

public class NotesActivity extends AppCompatActivity {
    String typedText;
    EditText inputTxt;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_notes);
        inputTxt = (EditText) findViewById(R.id.notes1);
    }

    @Override
    protected void onPause() {
        super.onPause();
        typedText = inputTxt.getText().toString();
    }


    @Override
    protected void onResume() {
        super.onResume();
        inputTxt.setText(typedText); 
    }            
}

Answer 1

When you destroy the activity even if you are setting typedText to something it will become null because the next time you launch this activity from other, a new instance will be created and old data will be lost. You have to store data with persistent storage options. https://developer.android.com/guide/topics/data/data-storage.html

To store data in SharedPreferences you can modify following code.

private final String PREFS_NAME = "packageName";

SharedPreferences sharedPref = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("typedText", inputTxt.getText().toString());
editor.commit();

And to retrieve the value you can do as following.

SharedPreferences sharedPref = getSharedPreferences(PREFS_NAME, 0);
String typedValue = sharedPref.getString("typedText", "defaultValue/null");

Answer 2

In parent call startActivityForResult(getApplicationContext(), NotesActivity.class) to call child activity which is NotesActivity.

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        Bundle extras = data.getExtras();
        String typedText = "" + extras.getString("TypedText");

    }
}

In the Child activity use below function to return 'typedText'

private void returnText() {
    Intent result = new Intent();
    String typedText = inputTxt.getText().toString();
    result.putExtra("TypedText", typedText);
    setResult(RESULT_OK, result);
} 


@Override
protected void onPause() {
    super.onPause();
    returnText();
}