Question

我在项目中使用了Realm 3.1.3和Realm Adapters 2.0，当我尝试使用

更新适配器时出现此错误

adapter.updateData(RealmManager.stationsDetailsDAO().loadSearch(newText.toLowerCase(), selectedLanguage, type));

这是抛出的错误

Attempt to invoke virtual method 'void io.realm.BaseRealm.checkIfValid()' on a null object reference

尝试从数据库查询时

这是我的代码：

public RealmList<Station> loadSearch(String query, String language, String type) {

    RealmList<Station> stationRealmList = new RealmList<>();

    mRealm.executeTransaction(realm -> mRealm.copyToRealm(stationRealmList)); 
    // To make it a Managed Object

    switch (type) {
        case "Language": {
            RealmQuery<Station> stationRealmQuery = mRealm.where(Station.class);
            stationRealmQuery.equalTo("language", language);
            RealmResults<Station> realmResults = stationRealmQuery.findAll();
            for (int i = 0; i < realmResults.size(); i++) {
                if (realmResults.get(i).getName().contains(query)) {
                    stationRealmList.add(realmResults.get(i));
                }

            }

            return stationRealmList;
        }
        case "Recent":
            HeaderSectionModel realmList = RealmManager.stationsDetailsDAO().loadHeaderData();
            for (int i = 0; i < realmList.getLanguageModelArrayList().size(); i++) {
                if (realmList.getLanguageModelArrayList().get(i).getName().contains(query)) {
                    stationRealmList.add(realmList.getLanguageModelArrayList().get(i));
                }
            }

            return stationRealmList;
        case "Genre": {
            RealmQuery<Station> stationRealmQuery = mRealm.where(Station.class);
            stationRealmQuery.equalTo("genreName", language);
            RealmResults<Station> realmResults = stationRealmQuery.findAll();


            for (int i = 0; i < realmResults.size(); i++) {
                if (realmResults.get(i).getName().contains(query)) {
                    stationRealmList.add(realmResults.get(i));
                }
            }

            return stationRealmList;
        }
    }


    return stationRealmList;
}

Answer 1

因为RealmList<Station> stationRealmList = new RealmList<>();不是链接的托管视图（如未使用getRealmListField() 从托管的RealmObject获取），所以RealmRecyclerViewAdapter 没有＆使用它。

解决方案是，您应该显示由RealmResults定义的RealmQuery，而不是手动尝试执行包含操作。

public RealmResults<Station> loadSearch(String query, String language, String type) { RealmQuery<Station> stationRealmQuery = mRealm.where(Station.class); if(query != null && !"".equals(query)) { stationRealmQuery.contains("name", query); } switch (type) { case "Language": stationRealmQuery.equalTo("language", language); break; case "Recent": // TODO do something about this one break; case "Genre": stationRealmQuery.equalTo("genreName", language); break; } return stationRealmQuery.findAll(); }

如果无法做到这一点，请使用常规RecyclerView.Adapter和您自己的RealmChangeListener。

null对象引用上的checkIfValid（）（Realm 3.1.3）

1 个答案: