导航抽屉中的操作与片段更改

Question

所以，我按照教程将滑动导航抽屉添加到我的应用程序（加上我自己的一些调整），但我有点困惑，可能是因为我不完全了解片段。基本上，我创建了一个溢出菜单，其中 Log Out 作为唯一选项，所以我可以测试我的登录系统。我想在我的导航抽屉中使用注销选项，这样我就可以摆脱那个溢出菜单，但我不知道要更改什么以便它注销而不是只显示被点击的片段的标题.虽然我问的是基本相同的问题，但如果我想创建某人在单击导航抽屉中的选项时正在查看的页面，我会在哪里做呢？在各自的片段中？

MainActivity.java

package me.paxana.alerta;

import android.app.Activity;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarDrawerToggle;
import android.app.Fragment;
import android.content.Intent;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;

import com.parse.ParseUser;

import java.util.ArrayList;
import java.util.List;

import butterknife.Bind;
import butterknife.ButterKnife;
import me.paxana.alerta.adapter.SlidingMenuAdapter;
import me.paxana.alerta.fragment.Fragment1;
import me.paxana.alerta.fragment.Fragment2;
import me.paxana.alerta.fragment.Fragment3;
import me.paxana.alerta.model.ItemSlideMenu;

public class MainActivity extends AppCompatActivity {
    public static final String TAG = MainActivity.class.getSimpleName();
    private List<ItemSlideMenu> listSliding;
    private SlidingMenuAdapter adapter;
    private ListView listViewSliding;
    private DrawerLayout drawerLayout;
    private android.support.v7.app.ActionBarDrawerToggle actionBarDrawerToggle;
    private Toolbar mToolbar;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);


        ParseUser currentUser = ParseUser.getCurrentUser();
             if (currentUser == null) {
                navigateToLogin();
            }

        else {
                Log.i(TAG, currentUser.getUsername());
            }

        listViewSliding = (ListView)findViewById(R.id.lv_sliding_menu);
        drawerLayout = (DrawerLayout)findViewById(R.id.drawer_layout);
        listSliding = new ArrayList<>();
        //add item for sliding list
        listSliding. add(new ItemSlideMenu(R.drawable.ic_action_settings, "Settings"));
        listSliding.add(new ItemSlideMenu(R.drawable.ic_action_about, "About"));
        listSliding.add(new ItemSlideMenu(R.drawable.ic_logout_black_48dp, "Log Out"));
        adapter = new SlidingMenuAdapter(this, listSliding);
        listViewSliding.setAdapter(adapter);


        //display icon to open/close slider
        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);
        assert getSupportActionBar() != null;
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        //set title
        setTitle(listSliding.get(0).getTitle());
        //item selected
        listViewSliding.setItemChecked(0, true);
        //close menu
        drawerLayout.closeDrawer(listViewSliding);
        //handle on item click
        listViewSliding.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //set title
                setTitle(listSliding.get(position).getTitle());
                //item selected
                listViewSliding.setItemChecked(position, true);
                //close menu
                drawerLayout.closeDrawer(listViewSliding);
            }

        });

        actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.drawer_opened, R.string.drawer_closed) {
            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                invalidateOptionsMenu();
            }

            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                invalidateOptionsMenu();
            }
        };

        drawerLayout.setDrawerListener(actionBarDrawerToggle);

    }

    private void navigateToLogin() {
        Intent intent = new Intent(this, LoginActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(intent);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
            inflater.inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if(actionBarDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }

        int itemId = item.getItemId();
        if (itemId == R.id.action_logout) {
            ParseUser.logOut();
            navigateToLogin();

        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        actionBarDrawerToggle.syncState();
    }
//create method replace fragment
    private void replaceFragment(int pos) {
        android.support.v4.app.Fragment fragment = null;
        switch (pos) {
            case 0:
                fragment = new Fragment1();
                    break;
            case 1:
                fragment = new Fragment2();
                break;
            case 2:
                fragment = new Fragment3();
                break;
            default:
                fragment = new Fragment1();
                break;
        }
        if(null != fragment) {
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();
            transaction.replace(R.id.main_content, fragment);
            transaction.addToBackStack(null);
            transaction.commit();

        }
    }
}

Fragment3（我尝试将注销选项添加到此片段，但无济于事。当我单击它时仍然会发生文本“注销”显示在屏幕上）

package me.paxana.alerta.fragment;

import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.parse.ParseUser;

import me.paxana.alerta.LoginActivity;
import me.paxana.alerta.R;

/**
 * A simple {@link Fragment} subclass.
 * Activities that contain this fragment must implement the
 * {@link Fragment3.OnFragmentInteractionListener} interface
 * to handle interaction events.
 * Use the {@link Fragment3#newInstance} factory method to
 * create an instance of this fragment.
 */
public class Fragment3 extends Fragment {
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public Fragment3() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment Fragment3.
     */
    // TODO: Rename and change types and number of parameters
    public static Fragment3 newInstance(String param1, String param2) {
        Fragment3 fragment = new Fragment3();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ParseUser.logOut();
        Intent intent = new Intent(Fragment3.this.getActivity(), LoginActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(intent);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment3, container, false);
        // Inflate the layout for this fragment
        return rootView;
    }

    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p/>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }
}

Answer 1

如果我明白您在寻找什么，您可以通过单击导航抽屉列表的注销元素来注销：

试试这个：

listViewSliding.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

          if (position == logOutIndex) { //You can do this if you know the position of the logOut button, e.g it's always at the end of the ListVIew

                ParseUser.logOut();
                navigateToLogin();
           }
        }
    });

Answer 2

我希望它有效：

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if(actionBarDrawerToggle.onOptionsItemSelected(item)) {
        return true;
    }

    int itemId = item.getItemId();
    if (itemId == R.id.action_logout) {
        //ParseUser.logOut();
        //navigateToLogin();
        //If you the latest activity was te LoginActivity it goues to the LoginActivity
           finish();

    }
    return super.onOptionsItemSelected(item);
}

或者，如果您尝试从抽屉中执行此操作，请将您的 fragment3 替换为：

 private void replaceFragment(int pos) {
    android.support.v4.app.Fragment fragment = null;
    switch (pos) {
        case 0:
            fragment = new Fragment1();
                break;
        case 1:
            fragment = new Fragment2();
            break;
        case 2:
            //fragment = new Fragment3();
              //If you the latest activity was te LoginActivity it goues to the LoginActivity

               finish();

            break;
        default:
            fragment = new Fragment1();
            break;
    }

Answer 3

这很难解释，因为你必须做很多事情才能让它发挥作用。 我的第一个想法是您将代码粘贴到 MainActivity.java 中的 switch case 中：

private void replaceFragment(int pos) {
    android.support.v4.app.Fragment fragment = null;
    switch (pos) {
        case 0:
            fragment = new Fragment1();
                break;
        case 1:
            fragment = new Fragment2();
            break;
        case 2:
            ParseUser.logOut();
            Intent intent = new Intent(Fragment3.this.getActivity(),LoginActivity.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
            startActivity(intent);
            if (getArguments() != null) {
               mParam1 = getArguments().getString(ARG_PARAM1);
               mParam2 = getArguments().getString(ARG_PARAM2);
            }
            fragment = new Fragment3();
            break;
        default:
            fragment = new Fragment1();
            break;
    }
    if(null != fragment) {
        android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
        android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.main_content, fragment);
        ...

我希望我理解你的正确，但这必须解决问题，如果你现在点击第三个片段，你必须注销。

如果我错了，请尽快回信，我会寻找其他解决方案；）