ReSharper的，"返回类型可以是IEnumerable的..."但为什么？ [英] Resharper, "Return type can be IEnumerable..." but why?

问题描述

我有像这样的界面......

I have an interface like so...

public interface IAccountRepository : IDisposable {
    IQueryable<Account> FindByUserId(int userId); //here, Resharper says "Return type can be IEnumerable<Account>"
}

但ReSharper的是在暗示我将其更改为的IEnumerable< ;帐户> FindByUserId（INT用户id）代替。

为什么会这样？那岂不是强制加载到内存中整个对象？我认为这将是更好地推迟执行，直到真正需要的对象呢？

Why is that so? Wouldn't it force the entire objects to be loaded into memory? I thought it would be better to defer the execution until the object is really needed?

推荐答案

这只是一个特定的实例一般规则。

This is just a specific instance of a general rule.

如果您正在返回一个类型 SomeClass的它实现一个接口或从另一个类继承，并在整个解决方案，您只使用返回的对象这是在基类/接口（所以你不要使用 SomeClass的宣布任何方法），ReSharper的将建议的方法你说，为了基类/接口更换返回的对象类型，使你的代码更通用。

If you are returning a type SomeClass which implements an interface or inherits from another class, and in your entire solution you only use methods on the returned object which are in the base class/interface (so you don't use any methods declared in SomeClass), ReSharper will suggest that you replace the type of the returned object with that of the base class/interface in order to make your code more general.

在这种情况下，你只使用方法在的IEnumerable< T> 接口的IQueryable< T> 派生自

In this case, you are only using methods of the IEnumerable<T> interface that IQueryable<T> derives from.

还请注意，这仅仅是一个的建议的，而不是一个警告或错误。如果你愿意，你可以放心地忽略这一点。

Note also that this is just a suggestion, not a warning or an error. You can safely ignore this if you want to.

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