tollbar返回主页

   //返回按钮的监听
        setSupportActionBar(root.tb);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        getSupportActionBar().setHomeButtonEnabled(true);

    }
// 创建option监听
    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        if (item.getItemId() == android.R.id.home) {
            finish();
        }
        return super.onOptionsItemSelected(item);
    }