java - 替换 fragment 并根据字符串名称而不是 ListView 项目位置启动 Activity

Question

根据我的 ListView ，如何用特定 fragment 替换详细信息容器或根据所选项目的字符串名称而不是列表中项目的位置启动特定 Activity ？我正在寻找类似 case string 而不是 case 0、case 1、case 2 等的东西。 inital but incorrect code suggestion 下的代码与我正在寻找的代码相似，但不是正确的解决方案。我们将不胜感激。

字符串

<string-array name="continent_names">
    //item 0    <item>@string/africa</item>
    //item 1    <item>@string/asia</item>
    //item 2    <item>@string/europe</item>
</string-array>

<string-array name="continent_descriptions">
    //item 0    <item>@string/africa_description</item>
    //item 1    <item>@string/asia_description </item>
    //item 2    <item>@string/europe_description </item>
</string-array>

fragment 世界.java

    public class FragmentWorld extends ListFragment implements SearchView.OnQueryTextListener {

    private WorldListAdapter mAdapter;

    public FragmentWorld() {
        // Required empty constructor
    }

    public static FragmentWorld newInstance() {
        return new FragmentWorld();
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_world, container, false);
        setHasOptionsMenu(true);
        initialize(view);
        return view;
    }

    List<World> list = new ArrayList<World>();
    private void initialize(View view) {
        String[] items = getActivity().getResources().getStringArray(R.array.continent_names);
        String[] itemDescriptions = getActivity().getResources().getStringArray(R.array.continent_descriptions);
        for (int n = 0; n < items.length; n++){
            World world = new World();
            world.setID();
            world.setName(items[n]);
            world.setDescription(itemDescriptions[n]);
            list.add(world);
        }

        mAdapter = new WorldListAdapter(list, getActivity());
        setListAdapter(mAdapter);
    }

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

                // get the adapter, then get the name from the adapter at that position
                WorldListAdapter adapter = (WorldListAdapter) parent.getAdapter();
                String country = adapter.getItem(position);

                if (mTwoPane) {
                    setItemNormal();
                    View rowView = view;
                    setItemSelected(rowView);

                    Fragment newFragment;
                    if (country.equals(view.getResources().getString(R.string.africa))) {
                        newFragment = new FragmentAfrica();
                    } else if (country.equals(view.getResources().getString(R.string.asia))) {
                        newFragment = new FragmentAsia();
                    } else if (country.equals(view.getResources().getString(R.string.europe))) {
                        newFragment = new FragmentEurope();
                    } else {
                        newFragment = new FragmentAfrica();
                    }
                    WorldActivity activity = (WorldActivity) view.getContext();
                    FragmentTransaction transaction = activity.getSupportFragmentManager().beginTransaction();
                    transaction.replace(R.id.detail_container, newFragment);
                    transaction.commit();
                } else {
                    Intent intent;
                    if (country.equals(view.getResources().getString(R.string.africa))) {
                        intent = new Intent(getActivity(), AfricaActivity.class);
                    } else if (country.equals(view.getResources().getString(R.string.asia))) {
                        intent = new Intent(getActivity(), AsiaActivity.class);
                    } else if (country.equals(view.getResources().getString(R.string.europe))) {
                        intent = new Intent(getActivity(), EuropeActivity.class);
                    } else {
                        intent = new Intent(getActivity(), AfricaActivity.class);
                    }
                    startActivity(intent);
                }
            }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        // Set up search view
        inflater.inflate(R.menu.menu_world, menu);
        MenuItem item = menu.findItem(R.id.action_search);
        SearchView searchView = (SearchView) MenuItemCompat.getActionView(item);
        searchView.setIconifiedByDefault(true);
        searchView.clearAnimation();
        searchView.setOnQueryTextListener(this);
        searchView.setQueryHint(getResources().getString(R.string.search_hint));

        View close = searchView.findViewById(R.id.search_close_btn);
        close.setBackgroundResource(R.drawable.ic_action_content_clear);
    }

    @Override
    public boolean onQueryTextSubmit(String newText) {
        return false;
    }

    @Override
    public boolean onQueryTextChange(String newText) {
        mAdapter.getFilter().filter(newText);
        return false;
    }
}

WorldListAdapter.java

public class WorldListAdapter extends BaseAdapter implements Filterable {

    private List<World> mData;
    private List<World> mFilteredData;
    private LayoutInflater mInflater;
    private ItemFilter mFilter;

    public WorldListAdapter (List<World> data, Context context) {
        mData = data;
        mFilteredData = new ArrayList(mData);
        mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        return mFilteredData.size();
    }

    @Override
    public String getItem(int position) {
        return mFilteredData.get(position).getName();
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        ViewHolder holder;
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.list_item_dualline, parent, false);
            holder = new ViewHolder();

            holder.title = (TextView) convertView.findViewById(R.id.item_name);
            holder.description = (TextView) convertView.findViewById(R.id.item_description);

            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.title.setText(mFilteredData.get(position).getName());
        holder.description.setText(mFilteredData.get(position).getDescription());

        return convertView;
    }

    @Override
    public Filter getFilter() {
        if (mFilter == null) {
            mFilter = new ItemFilter();
        }
        return mFilter;
    }

    /**
     * View holder
     */
    static class ViewHolder {
        private TextView title;
        private TextView description;
    }

    private class ItemFilter extends Filter {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults results = new FilterResults();

            if (TextUtils.isEmpty(constraint)) {
                results.count = mData.size();
                results.values = new ArrayList(mData);
            } else {
                //Create a new list to filter on
                List<World> resultList = new ArrayList<World>();
                for (World str : mData) {
                    if (str.getName().toLowerCase().contains(constraint.toString().toLowerCase())) {
                        resultList.add(str);
                    }
                }
                results.count = resultList.size();
                results.values = resultList;
            }
            return results;
        }


        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            if (results.count == 0) {
                mFilteredData.clear();
                notifyDataSetInvalidated();
            } else {
                mFilteredData = (ArrayList<World>)results.values;
                notifyDataSetChanged();
            }
        }
    }
}

初始但不正确的代码建议

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                if (mTwoPane) {
                    setItemNormal();
                    View rowView = view;
                    setItemSelected(rowView);
                    Fragment newFragment;
                    switch (position) {
                        case 0:
                            newFragment = new FragmentAfrica();
                            break;
                        case 1:
                            newFragment = new FragmentAsia();
                            break;
                        case 2:
                            newFragment = new FragmentEurope();
                            break;
                        default:
                            newFragment = new FragmentAfrica();
                            break;
                    }
                    WorldActivity activity = (WorldActivity) view.getContext();
                    FragmentTransaction transaction = activity.getSupportFragmentManager().beginTransaction();
                    transaction.replace(R.id.detail_container, newFragment);
                    transaction.commit();
                } else {
                    Intent intent;
                    switch (position) {
                        case 0:
                            intent = new Intent(getActivity(), AfricaActivity.class);
                            break;
                        case 1:
                            intent = new Intent(getActivity(), AsiaActivity.class);
                            break;
                        case 2:
                            intent = new Intent(getActivity(), EuropeActivity.class);
                            break;
                        default:
                            intent = new Intent(getActivity(), AfricaActivity.class);
                            break;
                    }
                    startActivity(intent);
                }
            }

            public void setItemSelected(View view) {
                View rowView = view;
                view.setBackgroundColor(Color.parseColor("#0099CC"));

                TextView tv0 = (TextView) rowView.findViewById(R.id.item_name);
                tv0.setTextColor(Color.parseColor("#FFFFFF"));

                TextView tv1 = (TextView) rowView.findViewById(R.id.item_description);
                tv1.setTextColor(Color.parseColor("#FFFFFF"));
            }

            public void setItemNormal() {
                for (int i = 0; i < listView.getChildCount(); i++) {
                    View v = listView.getChildAt(i);
                    v.setBackgroundColor(Color.TRANSPARENT);

                    TextView tv0 = ((TextView) v.findViewById(R.id.item_name));
                    tv0.setTextColor(Color.WHITE);

                    TextView tv1 = ((TextView) v.findViewById(R.id.item_description));
                    tv1.setTextColor(Color.parseColor("#B5B5B5"));
                }
            }
        });

Answer 1

您要做的是从父级获取适配器，然后从适配器获取国家/地区名称。

试试这个:

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

            // get the adapter, then get the name from the adapter at that position
            WorldListAdapter adapter = (WorldListAdapter) parent.getAdapter();
            String country = adapter.getItem(position);

            if (mTwoPane) {
                setItemNormal();
                View rowView = view;
                setItemSelected(rowView);

                Fragment newFragment;
                if (country.equals(view.getResources().getString(R.string.africa))) {
                    newFragment = new FragmentAfrica();
                } else if (country.equals(view.getResources().getString(R.string.asia))) {
                    newFragment = new FragmentAsia();
                } else if (country.equals(view.getResources().getString(R.string.europe))) {
                    newFragment = new FragmentEurope();
                } else {
                    newFragment = new FragmentAfrica();
                }
                WorldActivity activity = (WorldActivity) view.getContext();
                FragmentTransaction transaction = activity.getSupportFragmentManager().beginTransaction();
                transaction.replace(R.id.detail_container, newFragment);
                transaction.commit();
            } else {
                Intent intent;
                if (country.equals(view.getResources().getString(R.string.africa))) {
                    intent = new Intent(getActivity(), AfricaActivity.class);
                } else if (country.equals(view.getResources().getString(R.string.asia))) {
                    intent = new Intent(getActivity(), AsiaActivity.class);
                } else if (country.equals(view.getResources().getString(R.string.europe))) {
                    intent = new Intent(getActivity(), EuropeActivity.class);
                } else {
                    intent = new Intent(getActivity(), AfricaActivity.class);
                }
                startActivity(intent);
            }
        }

您还可以使用 Raghav 对带字符串的 switch 语句的建议进行比较。