Android - Back button in the title bar

Question

In many apps (Calendar, Drive, Play Store) when you tap a button and enter a new activity, the icon in the title bar turns into a back button, but for the app I am making, i

Answer 1

I saw so much complexes answer, so this is my code. Working here. You can achieve this in two ways.

1) Stardard android compatiblity

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.core.app.NavUtils;

import android.view.MenuItem;
import android.view.View;

public class EditDiscoveryActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_edit_discovery);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        /*toolbar.setNavigationIcon(R.drawable.ic_arrow_white_24dp);
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                finish();
            }
        });*/
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setDisplayShowHomeEnabled(true);
    }

    @Override
    public boolean onSupportNavigateUp() {
        onBackPressed();
        return true;
    }

}

2) Use a custom icon

If you want to use code in comments you just have to add this file in drawable, called ic_arrow_white_24dp.xml

With this code.

toolbar.setNavigationIcon(R.drawable.ic_arrow_white_24dp);
            toolbar.setNavigationOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    finish();
                }
            });

Hope it will helps some people here !