Data is not displayed in Fragment?

want to display data in listview on fragment, but can only display a listview background color

the location of the navigation bar should show the news data below, but it is empty.

mainactivity Code 


public class MainActivity extends FragmentActivity {


    private TabLayout tab_title;
    private ViewPager vp_pager;

    private List<String> list_title;                                      //tab
    private List<View> listViews;

    private View newsView;                                                //
    private View sportView;                                               //
    private View funView;                                                 //
    private View science;                                                 //

    private viewAdapter vAdapter;                                         //viewadapter

    private final static String TAG="MainActivity";


    private int[] tabImg;

    private ArrayList<NewsBean> newsBeans =null;

    private DrawerLayout drawerLayout;
    private RelativeLayout rightLayout;
    private ImageView leftMenu, rightMenu;
    private ListView mListView;
    private List<ContentModel> mList;

    private ArrayList<Data> datas = null;
    private FragmentManager fManager = null;
    private long exitTime = 0;

    private Context mContext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//
        //title
        requestWindowFeature(Window.FEATURE_NO_TITLE);

//        if (getSupportActionBar() != null){
//            getSupportActionBar().hide();
//        }
//        setContentView(R.layout.activity_main);
        setContentView(R.layout.main);
        mContext = this;



        //1.
        ListView lv_news =  findViewById(R.id.lv_news);
        System.out.println("lv_show");
        //2.list
        ArrayList<NewsBean> allNews = NewsUtils.getAllNews(mContext);
        NewsBean a = allNews.get(0);
        System.out.println("newsbean:PPPP"+a);
        //3.adapterlistview
        NewsAdapter newsAdapter = new NewsAdapter(mContext, allNews);
        lv_news.setAdapter(newsAdapter);


        //4.listview
        //lv_news.setOnItemClickListener(this);

        //
        initControls();
        viewChanage();

        initData();

        leftMenu = (ImageView) findViewById(R.id.leftmenu);
        rightMenu = (ImageView) findViewById(R.id.rightmenu);
        drawerLayout = (DrawerLayout) findViewById(R.id.drawerlayout);
        rightLayout = (RelativeLayout) findViewById(R.id.right);
        mListView = (ListView) findViewById(R.id.left_listview);


        System.out.println("");
        ContentAdapter adapter = new ContentAdapter(this,mList);
        mListView.setAdapter(adapter);

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

                ContentModel contentModel = (ContentModel) parent.getItemAtPosition(position);
                int i = contentModel.getId();
                switch (i){
                    case 1:
                        Intent intent = new Intent(MainActivity.this,LoginActivity.class);
                        startActivity(intent);
                        break;
                    case 2:
//                        Intent intent = new Intent(MainActivity.this,LoginActivity.class);
//                        startActivity(intent);
                        Toast.makeText(MainActivity.this,"",Toast.LENGTH_LONG).show();
                        break;

                    case 3:
//                        Intent intent = new Intent(MainActivity.this,LoginActivity.class);
//                        startActivity(intent);
                        Toast.makeText(MainActivity.this,"",Toast.LENGTH_LONG).show();
                        break;

                    case 4:
//                        Intent intent = new Intent(MainActivity.this,LoginActivity.class);
//                        startActivity(intent);
                        Toast.makeText(MainActivity.this,"",Toast.LENGTH_LONG).show();
                        break;
                }

//                FragmentTransaction bt = fm.beginTransaction();
//                switch ((int) id) {
//                    case 1:
//                        //bt.replace(R.id.content, new NewsFragment());
//
//                        Intent intent = new Intent(MainActivity.this,LoginActivity.class);
//                        startActivity(intent);
//
//                        break;
//                    case 2:
//                        bt.replace(R.id.content, new SubscriptionFragment());
//                        break;
//
//                    default:
//                        break;
//                }
                //bt.commit();
                //drawerLayout.closeDrawer(Gravity.LEFT);
            }
        });

        leftMenu.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this,"",Toast.LENGTH_LONG).show();
                drawerLayout.openDrawer(Gravity.LEFT);
            }
        });
        rightMenu.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                drawerLayout.openDrawer(Gravity.RIGHT);
            }
        });
        rightLayout.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                drawerLayout.closeDrawer(Gravity.RIGHT);
            }
        });

//        //1.Fragment
//        FragmentManager fragmentManager = getFragmentManager();
//        //2.
//        FragmentTransaction transaction = fragmentManager.beginTransaction();
//        //3.
//        FragmentTransaction replace = transaction.replace(R.id.lv_tt, new NewsFragment());
//        //4.commit
//        transaction.commit();


    }




    /**
     * 
     */
    private void initControls()
    {
        //title
        tab_title = (TabLayout)findViewById(R.id.tab_title);
        vp_pager = (ViewPager)findViewById(R.id.vp_pager);
        //initBottomNavigationBar();
        //bottom
        //tabLayout
        tabImg = new int[]{R.drawable.icon_three,R.drawable.icon_one,R.drawable.icon_two ,R.drawable.icon_four};
    }

    /**
     * viewpager view ,icon
     */
    private void viewChanage()
    {
        listViews = new ArrayList<>();
        LayoutInflater mInflater = getLayoutInflater();
        //title
        newsView = mInflater.inflate(R.layout.fragment_news, null);
        sportView = mInflater.inflate(R.layout.fragment_sports, null);
        funView = mInflater.inflate(R.layout.fragment_amusement, null);
        science = mInflater.inflate(R.layout.fragment_science,null);

        listViews.add(newsView);
        listViews.add(sportView);
        listViews.add(funView);
        listViews.add(science);


        list_title = new ArrayList<>();
        list_title.add("");
        list_title.add("");
        list_title.add("");
        list_title.add("");

        //TabLayout,tab
        //TabLayout.MODE_FIXED          tab,
        //TabLayout.MODE_SCROLLABLE;    // tabtab
        //                              
        tab_title.setTabMode(TabLayout.MODE_FIXED); //


//        tab_title.setTabMode(TabLayout.MODE_SCROLLABLE);
        //tablayout
        //tab_title.setPadding(20,20,20,20);

        //TabLayouttab
        tab_title.addTab(tab_title.newTab().setText(list_title.get(0)));
        tab_title.addTab(tab_title.newTab().setText(list_title.get(1)));
        tab_title.addTab(tab_title.newTab().setText(list_title.get(2)));
        tab_title.addTab(tab_title.newTab().setText(list_title.get(3)));

        vAdapter = new viewAdapter(this,listViews,list_title,tabImg);
        vp_pager.setAdapter(vAdapter);
        //tabLayoutviewpager
        tab_title.setupWithViewPager(vp_pager);
    }
    private void initData() {

        mList = new ArrayList<ContentModel>();
        mList.add(new ContentModel(R.drawable.icon_one, "", 1));
        mList.add(new ContentModel(R.drawable.icon_two, "", 2));
        mList.add(new ContentModel(R.drawable.icon_three, "", 3));
        mList.add(new ContentModel(R.drawable.icon_four, "", 4));
        mList.add(new ContentModel(R.drawable.icon_one, "", 5));
        mList.add(new ContentModel(R.drawable.icon_four, "", 6));
    }
}

Fragment section: 


public class NewsFragment extends Fragment {

    private ListView lv_news;
    private ListView list;
    private SimpleAdapter adapter;
    protected Context mContext;
//    @Override
//    public void onAttach(Activity activity) {
//        super.onAttach(activity);
//        this.mActivity = activity;
//    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        this.mContext =  context;

    }

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);


    }

    private ListView ListView;

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


        //view

        //View rootview=inflater.inflate(R.layout.fragment_news,container,false);

        View view = LayoutInflater.from(this.getActivity()).inflate(R.layout.fragment_news, null);




        //4.listview
        lv_news.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

        }
        });*/



        //1.
        ListView lv_news =  (ListView) view.findViewById(R.id.lv_newss);

        System.out.println("1111111");

        //2.list
        ArrayList<NewsBean> allNews = NewsUtils.getAllNews(getActivity());

        System.out.println("newsbean");
        //3.adapterlistview
        NewsAdapter newsAdapter = new NewsAdapter(getActivity(),allNews);
        lv_news.setAdapter(newsAdapter);

        //4.listview
        //lv_news.setOnItemClickListener(this);


        return view;
    }

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

main layout xml 

 <android.support.design.widget.TabLayout
            android:id="@+id/tab_title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_alignParentTop="true"
            android:background="@color/colorPrimary"
            app:tabIndicatorColor="@color/colorAccent"
            app:tabSelectedTextColor="@color/blue_light"
            app:tabTextColor="@color/material_orange" />
        <!--app:tabTextAppearance="@style/tablayoutIcon"-->

        <android.support.v4.view.ViewPager
            android:id="@+id/vp_pager"
            android:layout_width="fill_parent"
            android:layout_height="match_parent"
            android:layout_alignParentBottom="true"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_weight="1" />

fragment layout 


    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">



    <ListView
        android:id="@+id/lv_newss"
        android:layout_width="match_parent"
        android:layout_height="500dp"
        android:background="@color/colorPrimary">
    </ListView>



</LinearLayout><?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">



    <ListView
        android:id="@+id/lv_newss"
        android:layout_width="match_parent"
        android:layout_height="500dp"
        android:background="@color/colorPrimary">
    </ListView>



</LinearLayout>
Android
Mar.02,2021

background color. That means your ListView data has not been loaded successfully. Remove the ListView and replace it with an ordinary TextView to see if there is any content displayed

.

is there a problem with your data loading? 

    //2.list
    ArrayList<NewsBean> allNews = NewsUtils.getAllNews(getActivity());

is this asynchronous?

1, first rule out whether there is something wrong with the ListView layout, such as normal width and height.
2, exclude whether there is data in adapter data
3, then rule out whether there is a problem with data refresh in adapter
4, and then rule out whether your item is visible

.

Previous: Ask the question of getting multiple interface data from one interface at the same time.

Next: Js array recursive loop

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
© 2021 CodesHelper
Advertising Contact us About us
Menu