如何在第二个活动中设置onBackPressed

Question

I set the <button> in activity_main.xml

<Button
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:onClick="ReturnHome"
    android:text="Go Back"
    android:layout_marginBottom="79dp"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true" />

And now I'd like to add onBackPressed method in AnswerActivity

public class AnswerActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_answer);
    TextView textViewDisplayResult = (TextView) findViewById(R.id.text_view_display_result);

To be able to go back to previous page which is Fragment .

Can somebody guide me step by step how to do it?

Edit:

I wrote something like this

     super.onBackPressed();
        Intent returnIntent = new Intent();
        finish();

But it says 'variable "returnIntent" is never used'. How to fix it?

Answer 1

If you meant the physical button on the device, this is done by overriding:

@Override
public void onBackPressed() {
    FragmentManager fm = getActivity().getSupportFragmentManager();
    fm.popBackStack();
}

And your code:

super.onBackPressed();
    Intent returnIntent = new Intent();
    finish();

Shows returnIntent is never shown because you never called startActivity (intent). And you have to make sure you add a target.