想要使用片段从导航抽屉活动移动到另一个屏幕，以在所有屏幕上显示抽屉

Question

我正在尝试最后两天在我的抽屉活动旁边添加片段，以便在整个应用程序中看到导航抽屉。我已尝试过stackoverflow和其他许多方法，但仍然没有成功。然后我必须从第一个片段移动到第二个片段，依此类推，直到需要导航抽屉。当我从我的活动移动到任何片段时，我想替换除抽屉之外的整个视图。每个片段都有自己的layout.xml，就像一个活动（线性/相对布局作为父级）。

抽屉活动：

 public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

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

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.addDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);

    Button btnfragOne = (Button) findViewById(R.id.btnfrag_one);
    btnfragOne.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            FragOne fragment = new FragOne();
            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.frag2, fragment, fragment.getClass().getSimpleName()).addToBackStack(null).commit();

        }
    });

}

1st Fragment类：

public class FragOne extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    return inflater.inflate(R.layout.frag_one, container, false);
}

// 2nd Fragment类：

public class FragTwo extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    return inflater.inflate(R.layout.frag_two, container, false);
}

Answer 1

只需执行此任务，您必须覆盖onNavigationItemSelected中的Activity方法，该方法返回NavigationDrawer上所选片段的id。

试试这个，

@Override
public boolean onNavigationItemSelected(MenuItem item) {

    //calling the method displayselectedscreen and passing the id of selected menu

    displaySelectedFragment(item.getItemId());

    return true;
}

现在displaySelectedFragment，

private void displaySelectedScreen(int itemId) {

    //creating fragment object
    Fragment fragment = null;

    //initializing the fragment object which is selected
    switch (itemId) {

        case R.id.your_fragment_one_id:
            fragment = new FragOne();
            break;

        case R.id.your_fragment_two_id:
            fragment = new FragTwo();
            break;
    }

    //replacing the fragment
    if (fragment != null) {
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.main_layout_id_which_is_to_be_replace, fragment);
        ft.commit();
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.your_drawer_layout_id);
    drawer.closeDrawer(GravityCompat.START);
}

编辑 - 如果你想从FragOne导航到FragTwo。试试这个，

在你的Activity中创建一个方法，

public void showFragTwo(){

    FragmentManager manager = getSupportFragmentManager();
    FragTwo frag = new FragTwo();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.your_layout_id_which_is_to_be_replace, frag);
    transaction.commit();

}

然后在你的FragOne当你想要启动FragTwo时，从startFragTwo调用Activity方法，

((YourActivity)  getActivity()).showFragTwo();