Question

是否建议在Service Fabric actor中有一个列表？我想在用户角色中保留用户收藏夹。这种情况的最佳方法是什么？

Answer 1

是的，只要您将列表视为不可变。

状态管理器检索方法返回对象中的对象的引用本地记忆。仅在本地内存中修改此对象不会使它得以持久保存。从中检索对象时国家经理和修改后，必须重新插入州经理要永远得救。

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下面的UserInfo类型演示了如何定义不可变类型利用上述建议。

[DataContract]
// If you don’t seal, you must ensure that any derived classes are also immutable
public sealed class UserInfo {
   private static readonly IEnumerable<ItemId> NoBids = ImmutableList<ItemId>.Empty;

   public UserInfo(String email, IEnumerable<ItemId> itemsBidding = null) {
      Email = email;
      ItemsBidding = (itemsBidding == null) ? NoBids : itemsBidding.ToImmutableList();
   }

   [OnDeserialized]
   private void OnDeserialized(StreamingContext context) {
      // Convert the deserialized collection to an immutable collection
      ItemsBidding = ItemsBidding.ToImmutableList();
   }

   [DataMember]
   public readonly String Email;

   // Ideally, this would be a readonly field but it can't be because OnDeserialized
   // has to set it. So instead, the getter is public and the setter is private.
   [DataMember]
   public IEnumerable<ItemId> ItemsBidding { get; private set; }

   // Since each UserInfo object is immutable, we add a new ItemId to the ItemsBidding
   // collection by creating a new immutable UserInfo object with the added ItemId.
   public UserInfo AddItemBidding(ItemId itemId) {
      return new UserInfo(Email, ((ImmutableList<ItemId>)ItemsBidding).Add(itemId));
   }
}

更多信息：1和2

服务结构actor的状态和列表

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