WCF服务应该返回一个EntityObject还是一个POCO / DTO类？ [英] Should a WCF service return an EntityObject or a POCO/DTO class?

问题描述

我一直在使用EntityFramework查看很多WCF示例，并且大多数人似乎都会向客户端返回一些POCO或DTO类。

I've been looking at a lot of WCF examples using EntityFramework and most of them seem to return some kind of POCO or DTO class to the client.

我想知道为什么这是因为默认 EntityObject 包括 [DataContract] / code>属性和实现 INotifyPropertyChanged 。返回一个DTO或POCO类比一个 EntityObject （或者反之亦然）？有没有特定的情况，最好是使用一个返回值超过另一个？

I was wondering why this was since the default EntityObject includes the [DataContract] attributes and implements INotifyPropertyChanged. Is returning a DTO or POCO class better than an EntityObject (or vise versa)? And is there specific instances where it is better to use one return value over another?

推荐答案

作为一个最佳实践，你一定要它返回一个明确设计为数据合同并且没有持久性逻辑的DTO / POCO类。

As a best practice, you should definitely have it return a DTO/POCO class that is explicitly designed as a data contract and has no persistence logic.

原因是，如果传递了一个EntityObject，那么您正在制作假设服务的消费者将引用相同的数据上下文，这违反了明确边界的SOA原则。它降低了您的服务的可重用性。

The reason is, if you pass an EntityObject, you are making an assumption that the consumer of the service will have a reference to the same data context, and this violates the SOA tenet of explicit boundaries. It reduces the reusability of your service.

Microsoft在EntityObject上实现了DataContract可能支持其一些基于WCF的数据库访问工具，如RIA。 INotifyPropertyChanged用于WPF绑定支持，与WCF或数据合约无关。

It is probable that Microsoft implemented DataContract on the EntityObject to support some of their WCF-based database access tools like RIA. The INotifyPropertyChanged is for WPF binding support, and is not related to WCF or data contracts.

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