qq_花开花谢_0
由于stackoverflow上已有人提出过这个问题，并且解答也很好，我就直接搬运最高票过来，并稍作翻译。Encapsulationofbehaviorassociatedwithgettingorsettingtheproperty-thisallowsadditionalfunctionality(likevalidation)tobeaddedmoreeasilylater.对与get&set类属性有关的类的行为进行封装可以方便以后增加其他功能（比如验证）Hidingtheinternalrepresentationofthepropertywhileexposingapropertyusinganalternativerepresentation.用不同于内部的展现方式对外公布属性Insulatingyourpublicinterfacefromchange-allowingthepublicinterfacetoremainconstantwhiletheimplementationchangeswithoutaffectingexistingconsumers.避免对外接口发生变化——当实现发生变化时，对外接口不变，不会影响到现有的调用方Controllingthelifetimeandmemorymanagement(disposal)semanticsoftheproperty-particularlyimportantinnon-managedmemoryenvironments(likeC++orObjective-C).控制属性的生命周期和内存管理——在无内存管理的环境中尤其重要（比如C++和Objective-C）Providingadebugginginterceptionpointforwhenapropertychangesatruntime-debuggingwhenandwhereapropertychangedtoaparticularvaluecanbequitedifficultwithoutthisinsomelanguages.当属性的值在运行时发生变化的时候，提供一个调试入口——在某些语言中调试属性值的变化是很困难的Improvedinteroperabilitywithlibrariesthataredesignedtooperateagainstpropertygetter/setters-Mocking,Serialization,andWPFcometomind.提高与那些操作属性的getter/setter的库的互通性——比如Mocking（单测常用的东西,我平时也直接说Mock，不知道怎么翻译）,序列化,WPF等等Allowinginheritorstochangethesemanticsofhowthepropertybehavesandisexposedbyoverridingthegetter/settermethods.允许子类继承并覆写修改属性的行为的语义Allowingthegetter/settertobepassedaroundaslambdaexpressionsratherthanvalues.允许getter/setter作为lambda表达式而不是值进行传递Gettersandsetterscanallowdifferentaccesslevels-forexamplethegetmaybepublic,butthesetcouldbeprotected.getter/setter可以有不同的可访问性，比如get可以public而set则是protected