android - 抽屉导航 RecyclerView 项目单击 Activity

Question

我创建了一个抽屉导航，里面有一个 RecyclerView。我是从 YouTube 上了解到的。但是我在为它实现“onNavigationDrawerItemSelected”方法时遇到了麻烦。我想要做的是让用户能够点击列表中的项目，然后将它们导航到 Activity 而不是 Fragment。

我是android编程的新手，因此我对代码的理解很差。我到处查看在线教程，例如下面的链接，但它不起作用。我花了很多时间试图解决这个问题，但我得到的只是应用程序崩溃，不得不重新启动整个过程。如果有人可以帮助我，这对我来说意义重大

How to navigate to different activities through the navigation drawer

OnItemClickListener Navigation Drawer

http://blog.evizija.si/android-layout/

下面是我为 MainActivity、NavigationDrawer 和 NavigationDrawerAdapter 编写的代码。

抽屉导航 fragment :

public class NavigationDrawerFragment extends Fragment {

    private RecyclerView recyclerView;
    public static final String PREF_FILE_NAME = "testpref";
    public static final String KEY_USER_LEARNED_DRAWER = "user_learned_drawer";
    private ActionBarDrawerToggle mDrawerToggle;
    private DrawerLayout mDrawerLayout;
    private NavigationDrawerAdapter adapter;

    /*This is to tell the User that there is a navigation drawer*/
    private boolean mUserLearnedDrawer;
    private boolean mFromSavedInstanceState;
    private View containerView;

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


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mUserLearnedDrawer = Boolean.valueOf(readFromPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, "false"));
        if (savedInstanceState != null) {
            mFromSavedInstanceState = true;
        }
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
        recyclerView = (RecyclerView) layout.findViewById(R.id.navigation_drawer_list);
        adapter = new NavigationDrawerAdapter(getActivity(), getData());
        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        return layout;
    }


    //Change the Drawables and Text Here for the NavigationDrawer List Items
    public static List<NavigationDrawerItems> getData() {
        List<NavigationDrawerItems> data = new ArrayList<>();
        int[] icons = {R.drawable.ic_account_circle_black_36dp, R.drawable.ic_home_black_36dp, R.drawable.ic_language_black_36dp, R.drawable.ic_redeem_black_36dp, R.drawable.ic_settings_black_36dp};
        String[] titles = {"Restaurants", "Categories", "Planner", "About Us", "Settings"};
        for (int i = 0; i < titles.length && i < icons.length; i++) {
            NavigationDrawerItems current = new NavigationDrawerItems();
            current.iconId = icons[i];
            current.title = titles[i];
            data.add(current);
        }
        return data;
    }


    public void setUp(int fragmentId, DrawerLayout drawerLayout, Toolbar toolbar) {
        containerView = getActivity().findViewById(fragmentId);
        mDrawerLayout = drawerLayout;
        mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {


            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                if (!mUserLearnedDrawer) {
                    mUserLearnedDrawer = true;
                    saveToPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, mUserLearnedDrawer + "");
                }
                getActivity().invalidateOptionsMenu();
            }


            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                getActivity().invalidateOptionsMenu();
            }
        };
        if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
            mDrawerLayout.openDrawer(containerView);

        }
        mDrawerLayout.setDrawerListener(mDrawerToggle);
        mDrawerLayout.post(new Runnable() {
            @Override
            public void run() {
                mDrawerToggle.syncState();
            }
        });
    }


    public static void saveToPreferences(Context context, String preferenceName, String preferenceValue) {
        SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString(preferenceName, preferenceValue);
        editor.apply();
    }


    public static String readFromPreferences(Context context, String preferenceName, String defaultValue) {
        SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
        return sharedPreferences.getString(preferenceName, defaultValue);
    }

}

主要 Activity :

public class MainActivity extends ActionBarActivity {

    private Toolbar toolbar;
    private NavigationDrawerFragment drawerFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_appbar);

        /*======= This three statement below is to add the customized ToolBar including the "private" statement above and the navigation drawer =======*/
        toolbar = (Toolbar) findViewById(R.id.app_bar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        drawerFragment = (NavigationDrawerFragment)
                getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
        drawerFragment.setUp(R.id.fragment_navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout), toolbar);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();


        /*======= The term "navigate" is taken from the menu_main.xml file. Rename them when necessary =======*/
        /*======= The startActivity statement enables the icon to be clicked and brings to another activity =======*/
        if (id == R.id.navigate) {
            startActivity(new Intent(this, SubActivity.class));
        }

        return super.onOptionsItemSelected(item);
    }
}

抽屉导航适配器:

public class NavigationDrawerAdapter extends RecyclerView.Adapter<NavigationDrawerAdapter.MyViewHolder> {

    private LayoutInflater inflater;
    List<NavigationDrawerItems> data = Collections.emptyList();

    public NavigationDrawerAdapter(Context context, List<NavigationDrawerItems> data) {
        inflater = LayoutInflater.from(context);
        this.data = data;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.fragment_navigation_drawer_row, parent, false);
        MyViewHolder holder = new MyViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        NavigationDrawerItems current = data.get(position);
        holder.title.setText(current.title);
        holder.icon.setImageResource(current.iconId);
    }

    @Override
    public int getItemCount() {
        return data.size();
    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        TextView title;
        ImageView icon;

        public MyViewHolder(View itemView) {
            super(itemView);
            title = (TextView) itemView.findViewById(R.id.navigation_drawer_list_text);
            icon = (ImageView) itemView.findViewById(R.id.navigation_drawer_list_icon);
        }
    }
}

Answer 1

在你的适配器类中试试这个:

class MyViewHolder extends RecyclerView.ViewHolder {
      TextView title;
      ImageView icon;
      public MyViewHolder(View itemView) {
          super(itemView);
          itemView.setOnClickListener(new View.OnCLickListener() {
               @Override
               public void onClick(View v) {
                  Intent intent = new Intent(context, YourActivity.class);
                  context.startActivity(intent)
               }
          });                           
          itemView.findViewById(R.id.navigation_drawer_list_text);
          icon = (ImageView) itemView.findViewById(R.id.navigation_drawer_list_icon);
      }
}

你必须有一个对 context 变量的引用，你可以拥有它，你可以通过适配器类的构造函数中的赋值来获得它。

希望这对您有所帮助!