Android 导航抽屉回收器查看项目单击活动

我创建了一个导航抽屉，里面有一个RecyclerView。这是我从YouTube上学到的。但是，我很难为它实现“onNavigationDrawerItemSelected”方法。我想做的是让用户能够单击列表中的项目，并将它们导航到一个活动，而不是一个片段

我是android编程新手，因此我对代码理解不好。我在网上的教程上到处都找过，比如下面的链接，但都不起作用。我花了很多时间试图弄明白这一点，我得到的只是应用程序崩溃，不得不重新启动整个程序。如果有人能在这方面帮助我，那对我来说意义重大

以下是我为主要活动、NavigationDrawer和NavigationDrawerRadapter制作的代码

导航抽屉碎片：

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);
    }

}

导航雷达：

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);
        }
    }
}

公共类NavigationDrawerDatapter扩展了RecyclerView.Adapter{
私人充气机；
List data=Collections.emptyList（）；
公共导航抽屉编辑器（上下文、列表数据）{
充气器=充气器。从（上下文）；
这个数据=数据；
}
@凌驾
公共MyViewHolder onCreateViewHolder（视图组父级，int-viewType）{
视图=充气机。充气（R.layout.fragment\u navigation\u drawer\u row，parent，false）；
MyViewHolder=新的MyViewHolder（视图）；
报税表持有人；
}
@凌驾
公共无效onBindViewHolder（MyViewHolder，int位置）{
NavigationDrawerItems当前=data.get（位置）；
holder.title.setText（当前.title）；
holder.icon.setImageResource（当前.iconId）；
}
@凌驾
public int getItemCount（）{
返回data.size（）；
}
类MyViewHolder扩展了RecyclerView.ViewHolder{
文本视图标题；
图像视图图标；
公共MyViewHolder（查看项目视图）{
超级（项目视图）；
title=（TextView）itemView.findViewById（R.id.navigation\u drawer\u list\u text）；
icon=（ImageView）itemView.findViewById（R.id.navigation\u drawer\u list\u图标）；
}
}
}

在适配器类中尝试以下操作：

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);
      }
}

您必须有一个对

上下文
变量的引用，您可以拥有它，您可以通过在适配器类的构造函数中赋值来获得它

希望这有帮助
 在NavigationDrawerRadapter类中

您需要实现GestureDetector方法来检测项目的位置。
您可以通过编写以下代码来实现这一点

        final GestureDetector mGestureDetector = new GestureDetector(YOUR_ACTIVITY_NAME.this, new GestureDetector.SimpleOnGestureListener() {

            @Override public boolean onSingleTapUp(MotionEvent e) {
                return true;
            }

        });

然后可以实现addOnItemTouchListener，如：

mRecyclerView.addOnItemTouchListener(new RecyclerView.SimpleOnItemTouchListener() {
            @Override
            public boolean onInterceptTouchEvent(RecyclerView recyclerView, MotionEvent motionEvent) {
                View child = recyclerView.findChildViewUnder(motionEvent.getX(),motionEvent.getY());



                if(child!=null && mGestureDetector.onTouchEvent(motionEvent)){
                    Drawer.closeDrawers();
                    Toast.makeText(Scnd.this,"The Item Clicked is: "+recyclerView.getChildPosition(child),Toast.LENGTH_SHORT).show();


               int p=     recyclerView.getChildPosition(child);
                    if (p == 0){

                         Intent intent = new Intent(this, FirstActivity.class);

                         startActivity(intent);
                    } else if(p == 1){

                        Intent intent = new Intent(this,SecondActivity.class);

                        startActivity(intent);
                    }
                    else if(p == 2){

                      Intent mintent = new Intent(your_activity.this,to activity you want start.class);
                        startActivity(mintent);
                    }

                    child.setBackgroundColor(Color.WHITE);


                    return true;

                }

                return false;
            }

            @Override
            public void onTouchEvent(RecyclerView recyclerView, MotionEvent motionEvent) {

            }
        });

现在您可以检查位置2，活动将开始，而不是片段。
这个代码对我来说非常有用。。任何人都可以从中获得帮助。
尝试在适配器内设置onclick…您应该使用基本活动概念
mRecyclerView.addOnItemTouchListener(new RecyclerView.SimpleOnItemTouchListener() {
            @Override
            public boolean onInterceptTouchEvent(RecyclerView recyclerView, MotionEvent motionEvent) {
                View child = recyclerView.findChildViewUnder(motionEvent.getX(),motionEvent.getY());



                if(child!=null && mGestureDetector.onTouchEvent(motionEvent)){
                    Drawer.closeDrawers();
                    Toast.makeText(Scnd.this,"The Item Clicked is: "+recyclerView.getChildPosition(child),Toast.LENGTH_SHORT).show();


               int p=     recyclerView.getChildPosition(child);
                    if (p == 0){

                         Intent intent = new Intent(this, FirstActivity.class);

                         startActivity(intent);
                    } else if(p == 1){

                        Intent intent = new Intent(this,SecondActivity.class);

                        startActivity(intent);
                    }
                    else if(p == 2){

                      Intent mintent = new Intent(your_activity.this,to activity you want start.class);
                        startActivity(mintent);
                    }

                    child.setBackgroundColor(Color.WHITE);


                    return true;

                }

                return false;
            }

            @Override
            public void onTouchEvent(RecyclerView recyclerView, MotionEvent motionEvent) {

            }
        });