本节是翻译整理的WCF服务编程设计规范(8)，内容主要包括：服务托管、自托管代码、客户端代理类、客户端代理管理、客户端异常管理、数据契约、SOAP与REST。如何选择托管类型？，如何管理客户端代理？如何处理客户端异常？如何选择数据契约？如何选择SOAP与REST服务?给出了选择标准。 Service Hosting
服务托管
l Favor WAS Hosting when Server 2008 is an option
可以使用Server2008
的时候，推荐使用WAS
Ø Multiple protocol support IIS Hosting model and tools
l Favor IIS for external HTTP only services
Ø Better on-box scalability / availability through worker
Ø Better management tools
l Favor self-hosting for stateful services, callbacks, .NET Service Bus, debugging
状态服务、回调、.NET Service Bus
和调试推荐自托管 l Have a console-based debug self-host for development time
Ø Can be a Windows Service project that is used for production self-hosting with a mode switch for debugging
可以用于产品阶段托管在Windows
服务的项目类型，利于模型转换与调试 l Consider Dublin hosting in the future
将来考虑Dulbin
托管（Windows Application Server
） Self Host Code
自托管代码
l Do not put ServiceHost in a using statement in production code
不要是在产品的Using
代码块里使用ServiceHost
Ø Dispose can throw an exception that masks the real
Ø Exception thrown from Open call
Ø Explicitly call Close in try/catch, log/ deal with exception in catch
在try/catch
里明确调用Close
方法，在Catch
代码里Log
并处理异常 Client Proxy Classes
客户端代理类
l Favor static proxy class over ChannelFactory
Ø Connection caching in the base class in 3.5
Ø Place for encapsulation of common patterns
l Hand-code or micro-code generate proxy classes for internal services
Ø Share service contract and data contracts through libraries
Ø Explicit control over config file
l Add Service Reference for external services or when you want an async API on the client
为外部服务添加服务引用或者当你想在客户端使用异步API
的时候 Ø Clean up config after it destroys it
Ø Make sure to add references to data contract libraries before adding the service reference to avoid duplicate definitions
Ø Live with the duplicate service contract definition instead of needing to repeatedly clean up the proxy code
使用复制的服务契约定义来代替重复的清理代理代码的工作 Client Proxy Management
客户端代理管理
l Cache client proxies if frequent calls to avoid session establishment cost
Ø If secure / reliable session enabled
Ø Have to deal more cautiously with faulted proxies
u Check proxy state before using
u Get rid of proxy after exception
l Don’t put proxies in a using statement
Ø Dispose call might throw exception and mask real exception
Ø Explicitly close in a try/catch block, and if Close throws an exception, abort the proxy to ensure resource clean up
在try/catch
块里，清晰地关闭，并且，如果close
的时候抛出异常，终止代理确保资源释放 Client Exception Management
客户端异常管理
l All exceptions thrown from a service call derive from CommunicationException
所有的调用服务的异常都继承自CommunicationException
l FaultException could be wrapped unhandled exception on the client, or explicit error returned from the service
FaultException
可以被包装在一个客户端的未处理异常中，或者明确返回自服务 l FaultException<T> always an explicit error returned from the service
FaultException<T>
始终明确从服务返回的错误 Ø Any exception from a proxy call, safe close the proxy
Ø FaultException<T> - proxy is reusable
FaultException<T>-
代理是可以复用的 Data Contracts
数据契约
l Favor data contracts over serializable types
Ø More explicit model, better control over what the client sees
更清晰的模型，对于客户端说看到的数据进行更好的控制 l Implement IExtensibleDataObject
实现IExtensibleDataObject
接口 Ø Avoids dropping data that the service / client does not understand
l Avoid passing complex .NET specific types for interoperable services
Ø DataSets and Exception types
l Avoid XmlSerializer and MessageContracts except for interoperable scenarios and REST services
除了互操作的场景和REST
服务，避免XmlSerializer
（XML
序列化器）和MessageContracts
（消息契约） SOAP vs. REST
SOAP与REST
l Favor SOAP services when you are writing a service that only your code will consume
l Favor REST services for publicly exposed, data oriented services
当你的服务是公开暴露、面向数据时，推荐使用REST
本文转自 frankxulei 51CTO博客，原文链接：http://blog.51cto.com/frankxulei/320878 ，如需转载请自行联系原作者