当我第二次将数据从另一个活动发送到MainActivity时，我获得了我第一次获得的数据

Question

I develop a simple app with cards with 2 textViews. Have just 2 activities. On the second activity i put data and send it to MainActivity for showing it on the card. When i create the first card with data, everything good, but if i want to create another one with another data, i get on MainActivity exactly the same card with data from the first time. ` MainActivity:

public class MainActivity extends ActionBarActivity {
    private RecyclerView recyclerView;
    private RecyclerView.Adapter adapter;
    private RecyclerView.LayoutManager layoutManager;
    public ArrayList<DataObject> dataObject;
    FloatingActionButton fab;
    int i = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        dataObject = new ArrayList<>();
        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);
        layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        adapter = new RecyclerAdapter(dataObject);
        recyclerView.setAdapter(adapter);
        fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, AddNewCard.class);
                startActivityForResult(intent, 1);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(data==null)
            return;
        String title = data.getStringExtra("title");
        String text = data.getStringExtra("text");
        dataObject.add(i, new DataObject(title, text));
        i++;

    }
}

And the code of the second activity:

public class AddNewCard extends ActionBarActivity {
    TextView mTitle, mText;
    Button mButton;

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

    private void initElements() {
        mTitle = (TextView) findViewById(R.id.editTitle);
        mText = (TextView) findViewById(R.id.editGoal);
        mButton = (Button) findViewById(R.id.sendButton);
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.putExtra("title", mTitle.getText().toString());
                intent.putExtra("text", mText.getText().toString());
                setResult(RESULT_OK, intent);
                finish();
            }
        });

    }
}

Also i have DataObject class with 2 Strings, constructor and getters and recycler adapter which works fine.

Answer 1

An easier, faster, but not stronger way to pass data between activities is to use a public static classs with static variables. As I said before, this is maybe not the right way to do it, but it works. Is not rocket science, but it is very useful if you create small projects.