Realm 不断调用 onChange addChangeListener

Question

如果解释得不好，我深表歉意，我自己也很难理解。如果您指出任何您不理解的地方，我会尽力纠正任何问题。好的，我们开始吧。

几个类。（D&D sheet, sheet 有用户可以装备的武器，这是关于装备存储在列表中的所述武器）

片段activity - CombatFragment
在CombatFragment中声明的arrayadapter列表 - AttackListViewContentAdapter
领域对象 - Weapon
持有武器列表的领域对象 - Sheet
一些XML个文件（我不会在这里粘贴的代码因为SO有代码限制。content_combat, attack_list_item

到目前为止我收集到的是，当我创建一个新的 attackListViewContentAdapter 时，它会以快速且持续的速度循环。如此之多，以至于屏幕对我触摸任何小部件都没有反应。我做了一些事情，比如每次通过时记录一个数字，这样它就会一次又一次地显示出来。如果您需要这方面的信息，我可以告诉您我将日志放在哪里以及在我添加其他视图（行）时 Logcat 中显示的内容。

我相信这与一直被触发的 onChangedListener 有关变化。

为了 space 的利益，请注意我将使用缩写代码。我忽略了不相关的对话框和小部件之类的东西。因此，如果它似乎缺少某些东西或者您需要查看类，它可能在我在每个文件上方链接的文件中。

CombatFragment

public class CombatFragment extends Fragment {
@BindView(R.id.lv_attack_spellcasting_content)
ListView lv_attack_spellcasting_title;


@Nullable
@Override
public View onCreateView(final LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.content_combat, container, false);
    RealmList<Weapon> weaponList = sheet.getWeaponList();
    final AttackListViewContentAdapter attackListViewContentAdapter = new AttackListViewContentAdapter(getActivity(), sheet, realm, weaponList);
    weaponList.addChangeListener(new RealmChangeListener<RealmList<Weapon>>() {
        @Override
        public void onChange(RealmList<Weapon> weapons) {
            /* Gives the adaptor a kick to know that the weapon realm list has changed */
            attackListViewContentAdapter.notifyDataSetChanged();
            loopOnChanged++;
        }
    });
    lv_attack_spellcasting_title.setAdapter(attackListViewContentAdapter);
    playerInit();
    return rootView;
}

   // This is a fake method, this is just to show that the .add is in it's own method which is triggered by a button press and not in onCreate
   public void buttonPress() {
       sheet.getWeaponList().add(realm.createObject(Weapon.class));
   }
} `

AttackListViewContentAdapter

public class AttackListViewContentAdapter extends ArrayAdapter<Weapon> {
        public AttackListViewContentAdapter(Context context, Sheet sheet, Realm realm, List<Weapon> weaponList) {
        super(context, 0, weaponList);
        this.sheet = sheet;
        this.realm = realm;
    }
    @Override
    @NonNull
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null)
        //Because you're returning the view (AttachToRoot is false) the ArrayAdaptor (This class) will handle adding the view to the list.
        convertView = 
        LayoutInflater.from(getContext()).inflate(R.layout.attack_list_item, parent, false);
        return convertView;
    }
}

Weapon

public class Weapon extends RealmObject {
    @PrimaryKey
    int weaponID;
    //properties, set get methods etc.
}

Sheet

public class Sheet extends RealmObject {
    @PrimaryKey
    private int sheetID;
    private RealmList<Weapon> weaponList;

    public RealmList<Weapon> getWeaponList() {
        return weaponList;
    }

    public void setWeaponList(RealmList<Weapon> weaponList) {
        this.weaponList = weaponList;
    }
}

content_combat

            <ListView
            android:id="@+id/lv_attack_spellcasting_content"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"

            android:columnCount="7"
            android:rowCount="1" />

attack_list_item

里面什么都没有

Answer 1

您的问题是由于 AttackListViewContentAdapter class.

中的微调器小部件初始化错误所致

您必须在设置 setOnItemSelectedListener 之前设置微调器选择。
您必须检查您的微调器选择是否不等于当前选择，以避免 onChange 和 onItemSelected 方法之间的无限循环。我的意思是，你的 spinners onItemSelected 回调，执行一个领域交易，然后，这些交易触发你的 onChange 回调，最后，你的 onChange 回调调用 notifyDataSetChanged() 使循环再次开始进入无限循环。

要解决您的问题，您应该按照 AttackListViewContentAdapter.java:

中的后续步骤操作

A) 从 addWeaponToUI() 方法中删除以下行：

private void addWeaponToUI() {
    et_name_value.setText(weapon.getWeaponName());
    np_damage_number_of_die_value.setValue(weapon.getWeaponDamageNumberOfDie());
    SheetEnum.Ability ability = SheetEnum.Ability.getEnumValue(weapon.getWeaponAbilityBonusInt());
    tv_attack_bonus_value.setText(String.valueOf(sheet.getAbilityBonus(ability)));

    // REMOVE below lines!
    //s_damage_die_type_value.setSelection(weapon.getWeaponDamageDieTypeInt());
    //s_damage_type_value.setSelection(weapon.getWeaponDamageTypeInt());
    //s_ability_bonus_value.setSelection(weapon.getWeaponAbilityBonusInt());
}

B) 在 setOnItemSelectedListener() 之前调用微调器 setSelection()，然后检查所选项目是否不等于所选位置以避免无限循环：

ArrayAdapter<CharSequence> damageDieTypeAdapter = ArrayAdapter.createFromResource(getContext(), R.array.die_type, android.R.layout.simple_spinner_dropdown_item);
    s_damage_die_type_value.setAdapter(damageDieTypeAdapter);
    //Set selection before listener
    s_damage_die_type_value.setSelection(weapon.getWeaponDamageDieTypeInt());
    s_damage_die_type_value.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View v, final int position, long id) {
            //Check selected position is not equal to current position to avoid an infinite loop
            if (position != weapon.getWeaponDamageDieTypeInt()) {
                String[] value = getContext().getResources().getStringArray(R.array.die_type);
                realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    weapon.setWeaponDamageDieType(position);
                }
            });
        }
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
    }
});

C) 对 s_damage_type_value 和 s_ability_bonus_value 微调器重复 步骤 B

Realm 不断调用 onChange addChangeListener

Realm calling onChange addChangeListener continuously

java

android

realm

android-arrayadapter