如何以表明一个方法是不成功的 [英] How to indicate that a method was unsuccessful

问题描述

我有几个类似的方法，例如说。 CalculatePoint（...）和CalculateListOfPoints（...）。偶尔，他们可能不会成功，并需要指明本给调用者。对于CalculateListOfPoints，它返回一个泛型列表，我可以返回一个空列表，并要求调用者来检查这一点;但点是一个值类型，所以我不能返回空值有

I have several similar methods, say eg. CalculatePoint(...) and CalculateListOfPoints(...). Occasionally, they may not succeed, and need to indicate this to the caller. For CalculateListOfPoints, which returns a generic List, I could return an empty list and require the caller to check this; however Point is a value type and so I can't return null there.

我非常希望的方法来'看'类似。一种解决方案可能是将其定义为

Ideally I would like the methods to 'look' similar; one solution could be to define them as

public Point CalculatePoint(... out Boolean boSuccess);
public List<Point> CalculateListOfPoints(... out Boolean boSuccess);

或可选择地返回一个点？对于CalculatePoint，并返回null来表示失败。这将意味着不得不投回到非可空类型，虽然，这似乎是过分了。

or alternatively to return a Point? for CalculatePoint, and return null to indicate failure. That would mean having to cast back to the non-nullable type though, which seems excessive.

另一条路线是返回布尔boSuccess，有结果（点或列表）作为一个出参数，并呼吁他们TryToCalculatePoint或东西...

Another route would be to return the Boolean boSuccess, have the result (Point or List) as an 'out' parameter, and call them TryToCalculatePoint or something...

什么是最好的做法？

编辑：我不想使用流量控制例外！失败是预料有时

I do not want to use Exceptions for flow control! Failure is sometimes expected.

推荐答案

就个人而言，我想我会用同样的想法的TryParse（）：使用out参数输出的实际价值，并返回一个布尔值，指示调用是否成功与否

Personally, I think I'd use the same idea as TryParse() : using an out parameter to output the real value, and returning a boolean indicating whether the call was successful or not

公共BOOL CalculatePoint（...出点结果） ;

我不使用异常的正常行为（如果你希望的功能，不是为某些条目工作）的粉丝。

I am not a fan of using exception for "normal" behaviors (if you expect the function not to work for some entries).

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