Question

我正在尝试使用SearchView实现一个简单的搜索按钮，以在RecyclerView中查找项目。但是，此搜索按钮破坏了我的排序功能，因为在输入SearchView后无法再对RecyclerView进行排序。

这是我的活动

    private void sortAscending() {
        Collections.sort(stationList, (station1, station2) -> {
            if (station1.getData().getCurrent().getPollution().getAqius() > station2.getData().getCurrent().getPollution().getAqius()) {
                return 1;
            } else if (station1.getData().getCurrent().getPollution().getAqius() < station2.getData().getCurrent().getPollution().getAqius()) {
                return -1;
            } else {
                return 0;
            }
        });
    }

    private void sortDescending() {
        Collections.sort(stationList, (station1, station2) -> {
            if (station1.getData().getCurrent().getPollution().getAqius() > station2.getData().getCurrent().getPollution().getAqius()) {
                return -1;
            } else if (station1.getData().getCurrent().getPollution().getAqius() < station2.getData().getCurrent().getPollution().getAqius()) {
                return 1;
            } else {
                return 0;
            }
        });
    } 


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //Inflate the menu here
        getMenuInflater().inflate(R.menu.list_menu, menu);
        MenuItem searchItem = menu.findItem(R.id.item_search);
        SearchView searchView = (SearchView) searchItem.getActionView();
        searchView.setOnQueryTextListener(this);
        return true;
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        //A String for the message to be displayed in a Toast
        String msg = "";
        //Switch and case on the MenuItem object's id
        switch (item.getItemId()) {
            case R.id.sort_ascending:
                msg = "sorting by ascending.";
                sortAscending();
                Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
                break;
            case R.id.sort_descending:
                msg = "sorting by descending.";
                sortDescending();
                Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
                break;
        }
        adapter.notifyDataSetChanged();
        return super.onOptionsItemSelected(item);
    }
    @Override
    public boolean onQueryTextChange(String newText) {
        filter(newText.toLowerCase());
        return true;
    }

    private void filter(String text) {
        ArrayList<Station> filteredList = new ArrayList<>();

        for (Station item : stationList) {
            if (item.getData().getCity().toLowerCase().contains(text.toLowerCase())) {
                filteredList.add(item);
            }
        }

        adapter.filterList(filteredList);
        adapter.notifyDataSetChanged();
    }
    @Override
    public boolean onQueryTextSubmit(String query) {
        return false;
    }

现在，我怀疑它与onOptionsItemSelected方法有关，因为当用户单击菜单上的搜索按钮时，我那里没有任何东西可以做些事情。

这是RecyclerView的Adapter类，为简单起见删除了其他功能。

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        //...set text and information from ArrayList
        //Launch an activity and user clicks on an item in RecyclerView
        holder.itemView.setOnClickListener(view -> {
            Intent intent = new Intent(context, CityActivity.class);
            context.startActivity(intent);
        });
    }
//Function to set the ArrayList to the filtered list
//filteredList ArrayList is passed in from filter() in Activity
    public void filterList(ArrayList<Station> filteredList) {
        stationList = filteredList;
    }

这是菜单的XML：

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item android:id="@+id/item_sort"
        android:icon="@drawable/ic_sort_black_24dp"
        android:title="Sort"
        app:showAsAction="ifRoom">

        <menu>
            <item android:id="@+id/sort_ascending"
                android:title="Sort by ascending"/>
            <item android:id="@+id/sort_descending"
                android:title="Sort by descending"/>
        </menu>
</item>

    <item android:id="@+id/item_search"
        android:icon="@drawable/ic_search_black_24dp"
        android:title="Search"
        app:showAsAction="always"
        app:actionViewClass="android.support.v7.widget.SearchView"/>
</menu>

我无法弄清楚为什么在将信息输入SearchView并将其删除后为什么RecyclerView返回其正常状态，为什么我不能使用排序功能（升序和降序）对RecyclerView进行排序。

Answer 1

我通过检查文本长度是否为零来解决了我的问题，这意味着没有输入文本并且用户没有使用搜索。然后，我只调用filterList函数将当前stationList设置为要显示的那个。

    private void filter(String text) {
        if (text.length() == 0) {
            adapter.filterList(stationList);
        } else {
            ArrayList<Station> filteredList = new ArrayList<>();

            for (Station item : stationList) {
                if (item.getData().getCity().toLowerCase().contains(text.toLowerCase())) {
                    filteredList.add(item);
                }
            }

            adapter.filterList(filteredList);
        }
    }

为了清楚起见，我还将adapter.notifyDataSetChanged();移到了filterList函数中。

使用SearchView过滤器后，无法对RecyclerView进行排序

1 个答案: