Back action button on toolbar of menu item in drawer layout not working

Question

I've a drawer layout in my main activity. On selecting one of its menu item i.e Social (in my case), it jumps to another activity containing fragments tab layout. The toolbar in my Social activity has a back button <- like this. I want this to work and return to main content activity but i don't know :

• what to code for this?

• where should i do this? Here is the code of Social.Java , where i think needs some change for back button appearing automatically on toolbar but not working.

  @Override
  
    protected void onCreate(Bundle savedInstanceState) {
  
   super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_social);
  
  
       toolbar = (Toolbar) findViewById(R.id.toolbar);
  
      setSupportActionBar(toolbar);
  
          getSupportActionBar().setDisplayHomeAsUpEnabled(true);
  
          viewPager = (ViewPager) findViewById(R.id.viewpager);
          setupViewPager(viewPager);
  
          tabLayout = (TabLayout) findViewById(R.id.tabs);
          tabLayout.setupWithViewPager(viewPager);
      }
  

Answer 1

First step:Add this code in onCreat

ActionBar actionBar = getSupportActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);

Step:2 override onOptionItemSelected

  @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                finish();
                return true;
        }

        return super.onOptionsItemSelected(item);
    }

Answer 2

Try this way

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ...

    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    getSupportActionBar().setHomeButtonEnabled(true);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    ....
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId() == android.R.id.home) {
        // do your work
    }
    return super.onOptionsItemSelected(item);
}