android - Realm 搜索的复杂排序，多个 RealmResults 的联合

Question

我在我的开源 Linux 命令库项目中用 realm 替换了 sqlite。到目前为止一切顺利，但现在我遇到了问题。

我正在使用 RealmBaseAdapter 在带有搜索界面的 ListView 中显示所有命令。对于搜索，下面狙击的 Realm 会按如下顺序排列结果:

查询:测试

结果:

• l2测试
• rc测试
• 测试

• 测试参数

  RealmResults<Command> commands = mRealm.where(Command.class).contains("name", query).findAll();
  mAdapter.updateRealmResults(commands);
  

使用旧的 sqlite 逻辑，顺序是这样的:

结果:

• 测试
• 测试参数
• l2测试
• rc测试

return getReadableDatabase().rawQuery("Select * from "+ CommandsDBTableModel.TABLE_COMMANDS + "WHERE "+ CommandsDBTableModel.COL_NAME + "LIKE '%"+ query + "%' "+ "ORDER BY "+ CommandsDBTableModel .COL_NAME + "= '"+ query + "' DESC,"+ CommandsDBTableModel.COL_NAME + "LIKE '"+ query + "%' DESC", null);

是不是也可以用realm来实现呢？这是项目的链接 https://github.com/SimonSchubert/LinuxCommandBibliotheca

Answer 1

谢谢你们，你们帮了我很多，解决了这个问题。 @Mateusz Herych @EpicPandaForce

这是自定义适配器:

public abstract class RealmMultiAdapter<T extends RealmObject> extends BaseAdapter {

    private final RealmChangeListener<T> realmChangeListener = new RealmChangeListener<T>() {
        @Override
        public void onChange(RealmResults<T> t) {
            notifyDataSetChanged();
        }
    };

    protected LayoutInflater inflater;
    protected List<RealmResults<T>> realmResults;
    protected Context context;

    public RealmMultiAdapter(Context context, List<RealmResults<T>> realmResults, boolean automaticUpdate) {
        if (context == null) {
            throw new IllegalArgumentException("Context cannot be null");
        }
        this.context = context;
        this.realmResults = realmResults;
        this.inflater = LayoutInflater.from(context);
        for(RealmResults<T> results : realmResults) {
            results.addChangeListener(realmChangeListener);
        }
    }

    /**
     * Returns how many items are in the data set.
     *
     * @return count of items.
     */
    @Override
    public int getCount() {
        if (realmResults == null) {
            return 0;
        }
        int count = 0;
        for(RealmResults<T> realmResult : realmResults) {
            count += realmResult.size();
        }
        return count;
    }

    /**
     * Returns the item associated with the specified position.
     *
     * @param i index of item whose data we want.
     * @return the item at the specified position.
     */
    @Override
    public T getItem(int i) {
        if (realmResults == null || realmResults.size()==0) {
            return null;
        }
        int count = 0;
        for(RealmResults<T> realmResult : realmResults) {
            if(i<realmResult.size()+count) {
                return realmResult.get(i-count);
            }
            count += realmResult.size();
        }
        return null;
    }

    /**
     * Returns the current ID for an item. Note that item IDs are not stable so you cannot rely on the item ID being the
     * same after {@link #notifyDataSetChanged()} or {@link #updateRealmResults(List<RealmResults<T>>)} has been called.
     *
     * @param i index of item in the adapter.
     * @return current item ID.
     */
    @Override
    public long getItemId(int i) {
        // TODO: find better solution once we have unique IDs
        return i;
    }

    /**
     * Updates the RealmResults associated to the Adapter. Useful when the query has been changed.
     * If the query does not change you might consider using the automaticUpdate feature.
     *
     * @param queryResults the new RealmResults coming from the new query.
     */
    public void updateRealmResults(List<RealmResults<T>> queryResults) {
        for(RealmResults<T> results : realmResults) {
            if(results.isValid()) {             
                results.removeChangeListener(realmChangeListener);
            }
        }
        this.realmResults = queryResults;
        for(RealmResults<T> results : realmResults) {
            results.addChangeListener(realmChangeListener);
        }
        notifyDataSetChanged();
    }
}

基本上，我用 RealmResults 列表替换了单个 RealmResult，并修改了 getItem() 和 getCount() 方法。

    // before
    protected RealmResults<T> realmResults;
    // after
    protected List<RealmResults<T>> realmResults;

这就是我更新搜索的方式

    List<RealmResults<Command>> results = new ArrayList<>();
    results.add(mRealm.where(Command.class).equalTo("name", query).findAll());
    results.add(mRealm.where(Command.class).beginsWith("name", query).notEqualTo("name", query).findAll());
    results.add(mRealm.where(Command.class).contains("name", query).not().beginsWith("name", query).notEqualTo("name", query).findAll());

    mAdapter.updateRealmResults(results);