ios - CoreStore 创建对象并成功返回

Question

我使用此代码创建一个对象：

CoreStore.perform(
            asynchronous: { (transaction) -> Void in
                let summary = transaction.create(Into<SummaryEntity>())

        },
            completion: { _ in }
        )

完成后，我想返回刚刚创建的摘要对象。

这个怎么做？

我做了类似的事情，但不确定我们需要很多解包和fetchExisting​​功能

CoreStore.perform(
            asynchronous: { (transaction) -> Routine? in

                let routine = try! transaction.importUniqueObject(
                    Into<Routine>(),
                    source: routineDictionary)

                return routine
        },
            success: { (transactionRoutine) in

                guard let unwrappedTransactionRoutine = transactionRoutine else {
                    return
                }

                let routine = CoreStore.fetchExisting(unwrappedTransactionRoutine)

                guard let unwrappedRoutine = routine else {
                    return
                }

                completion(.data(unwrappedRoutine))
        },
            failure: { (error) in
                // ...
        }
        )

这是从 展开的错误fetchExisting：

Answer 1

我不确定你在问什么，因为你的例子完全不同。

如果您想创建一个对象，您将执行与导入相同的操作。transaction.create 不返回可选值，因此只需在第一个闭包中返回对象：

CoreStore.perform(asynchronous: { (transaction) -> SummaryEntity in
    let summary = transaction.create(Into<SummaryEntity>())
    return summary
}, success: { (summary) in
    let fetchedSummary = CoreStore.fetchExisting(summary)
    completion(.data(fetchedSummary))
}, failure: { (error) in
    // ...
})