单击列表项时 ViewPager 变为空白

Question

我有一个 table 如下所示。我的问题是：在列表视图中显示三个列表

Letter

Number

Word

但是当我点击任何列表项时，查看寻呼机滑动视图显示但仍然空白，那里没有数据。也没有页面标题显示。在 Logcat 中没有错误显示。

这是 ListNavAdapter

public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    ArrayAdapter arrayAdapter;
    ArrayList<String> listItem = new ArrayList<>();
    final ListView listView = (ListView) view.findViewById(R.id.list);
    SQLiteDatabase sqLiteDatabase = SqliteDatabase.getInstance(this.getContext()).getWritableDatabase();
    Cursor cursor = sqLiteDatabase.rawQuery("SELECT HEADER FROM MyData group by HEADER", new String[]{});

    if (cursor.getCount() == 0) {
        Toast.makeText(getActivity(), "No Data to show", Toast.LENGTH_LONG).show();
    } else {
        while (cursor.moveToNext()) {
            listItem.add(cursor.getString(0));
        }
        arrayAdapter = new ArrayAdapter<>(getActivity(), android.R.layout.simple_list_item_1, listItem);
        listView.setAdapter(arrayAdapter);
    }
    listView.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            Intent intent=new Intent(getActivity(), SwipeNav.class);
            intent.putExtra(ID_EXTRA, (String)adapterView.getItemAtPosition(i));
            startActivity(intent);
        }
});

这是 SwipeNavactivity

if (getIntent().hasExtra(ListNavAdapter.ID_EXTRA)) {
    String myInt = (getIntent().getStringExtra(ListNavAdapter.ID_EXTRA));
    listSwipePagerAdapter = new ListSwipePagerAdapter(getSupportFragmentManager(), this);
    viewPager = (ViewPager) findViewById(R.id.pager);
    viewPager.setAdapter(listSwipePagerAdapter);

这是来自 ListSwipePagerAdapter

public Fragment getItem(int i) {
    String myInt=ListNavAdapter.ID_EXTRA;
    ArrayList<String> listItem = new ArrayList<String>();
    SQLiteDatabase sqLiteDatabase = SqliteDatabase.getInstance(context).getWritableDatabase();
    Cursor cursor = sqLiteDatabase.rawQuery("SELECT NAME FROM MyData WHERE HEADER=?", new String[]{"myInt"});
    if (cursor.getCount() == 0) {
    } else {
        while (cursor.moveToNext()) {
            listItem.add(cursor.getString(0));
        }
    }
    Object[] mStringArray = listItem.toArray();
    Fragment fragment = new AFragment();
    Bundle args = new Bundle();
    assert mStringArray != null;
    args.putString(AFragment.ARG_OBJECT, (String)mStringArray[i]);
    fragment.setArguments(args);
    return fragment;
}

@Override
public int getCount() {
    String myInt=ListNavAdapter.ID_EXTRA;
    ArrayList<String> listItem = new ArrayList<>();
    SQLiteDatabase sqLiteDatabase = SqliteDatabase.getInstance(context).getWritableDatabase();
    Cursor cursor = sqLiteDatabase.rawQuery("SELECT NAME FROM MyData WHERE HEADER=?", new String[]{"myInt"});
    while (cursor.moveToNext()) {
        listItem.add(cursor.getString(cursor.getColumnIndex("NAME")));
    }
    return listItem.size();
}

@Override
public CharSequence getPageTitle(int position) {

    //return tabTitleArray[position];
    return "Object " + (position + 1);
}

这是 AFragment class

Bundle args = getArguments();
((TextView) rootView.findViewById(R.id.text1)).setText(args.getString(ARG_OBJECT));
return rootView;

Answer 1

我的问题已经解决了

为了在 SwipeNav 中显示数据 Activity，数据应该从 ListNavAdapter 传递到 ListSwipePagerAdapter。但是意图被发送到 SwipeNav。 HEADER 未显示在 ListSwipePagerAdapter 中。所以 ViewPager 变成空白。

我已经使用共享首选项解决了这个问题。

单击列表项时 ViewPager 变为空白

ViewPager becomes blank when click on list item

java

sqlite

android

android-viewpager