Question

我有一个Recyclerview来显示项目列表，我从Realm数据库中获取数据并将其存储在ArrayList中。但是当我尝试为特定位置更新特定的BoxItem时，它会向我显示这样的错误。

FATAL EXCEPTION: main                                         Process: one.thebox.android, PID: 7236
                                                              java.lang.IllegalStateException: Changing Realm data can only be done from inside a transaction.
                                                                  at io.realm.internal.Table.throwImmutable(Table.java:1138)
                                                                  at io.realm.internal.Table.checkImmutable(Table.java:924)
                                                                  at io.realm.internal.UncheckedRow.setLong(UncheckedRow.java:195)
                                                                  at io.realm.BoxItemRealmProxy.realmSet$quantity(BoxItemRealmProxy.java:590)
                                                                  at one.thebox.android.Models.BoxItem.setQuantity(BoxItem.java:347)
                                                                  at one.thebox.android.adapter.SearchDetailAdapter$SearchedItemViewHolder.updateQuantityInCart(SearchDetailAdapter.java:870)
                                                                  at one.thebox.android.adapter.SearchDetailAdapter$SearchedItemViewHolder.access$1900(SearchDetailAdapter.java:492)
                                                                  at one.thebox.android.adapter.SearchDetailAdapter$SearchedItemViewHolder$7.onClick(SearchDetailAdapter.java:786)
                                                                  at android.view.View.performClick(View.java:4780)
                                                                  at android.view.View$PerformClick.run(View.java:19866)
                                                                  at android.os.Handler.handleCallback(Handler.java:739)
                                                                  at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                  at android.os.Looper.loop(Looper.java:135)
                                                                  at android.app.ActivityThread.main(ActivityThread.java:5254)
                                                                  at java.lang.reflect.Method.invoke(Native Method)
                                                                  at java.lang.reflect.Method.invoke(Method.java:372)
                                                                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                                                                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

请在此处找到几个代码 - ArrayList box;

boxItem.setQuantity(quantity);
CartHelper.updateQuantityInCart(boxItem, quantity);
boxItems.get(position).setQuantity(quantity);
notifyItemChanged(position);

这里显示错误，无法修改数组列表中的对象

BoxItem -

public class BoxItem extends RealmObject implements Serializable {
 private int quantity;
 @PrimaryKey
private String uuid;

 public String getUuid() {
    return uuid;
}

public void setUuid(String uuid) {
    this.uuid = uuid;
}
   public int getQuantity() {
    return quantity;
}

public void setQuantity(int quantity) {
    this.quantity = quantity;
}
}

CartHelper-是一个更新Realm数据库中数据的类 -

 public static void updateQuantityInCart(final BoxItem boxItem, final int quantity) {
    Realm realm = TheBox.getRealm();
    realm.beginTransaction();
    BoxItem boxItem1 = realm.where(BoxItem.class).equalTo("uuid", boxItem.getUuid()).findFirst();
    if (boxItem1 != null) {
        boxItem1.setQuantity(quantity);
    }
    realm.commitTransaction();
}

updateQuantityInCart()是Adapter类中的一个方法，当我们想要更新recyclerview的任何项时调用它。就像我们想要更新特定项目的数量一样

Answer 1

看起来您正在尝试修改事务之外的Realm对象，这是不允许的。您应在beginTransaction()

等任何更新之间添加commitTransaction()和CartHelper.updateQuantityInCart(boxItem, quantity);

// Obtain a Realm instance
Realm realm = Realm.getDefaultInstance();

realm.beginTransaction();

//... add or update objects here ...

realm.commitTransaction();

在后台线程中执行的另一个最佳方法可能是：

realm.executeTransactionAsync

无法使用将RealmObject扩展为常规java对象的java类

1 个答案: