在泛型类型的构造函数中使用C＃params关键字 [英] Using C# params keyword in a constructor of generic types

问题描述

我在C＃泛型类有2个构造函数：

I have a generic class in C# with 2 constructors:

public Houses(params T[] InitialiseElements)
{}
public Houses(int Num, T DefaultValue)
{}

使用INT作为泛型类型构造一个对象，并传递两个整数作为参数会导致不正确的构造函数被调用（从我的观点来看）。

Constructing an object using int as the generic type and passing in two ints as arguments causes the 'incorrect' constructor to be called (from my point of view).

例如。 房屋及LT; INT＆GT;房子=新房＆LT; INT＆GT;（1,2） - 调用第二construtor。传入整数任何其他数量到构造函数将调用第一个构造函数。

E.g. Houses<int> houses = new Houses<int>(1,2) - calls the 2nd construtor. Passing in any other number of ints into the constructor will call the 1st constructor.

有没有解决这个其他任何方式不是删除了params关键字，并迫使用户通过T的阵列使用第一个构造函数是什么时候？

Is there any way around this other than removing the params keyword and forcing users to pass an array of T when using the first constructor?

推荐答案

一个更明确的解决办法是有两个静态工厂方法。如果你把这些变成非泛型类，你也可以从类型推断受益：

A clearer solution would be to have two static factory methods. If you put these into a nongeneric class, you can also benefit from type inference:

public static class Houses
{
    public static Houses<T> CreateFromElements<T>(params T[] initialElements)
    {
        return new Houses<T>(initialElements);
    }

    public Houses<T> CreateFromDefault<T>(int count, T defaultValue)
    {
        return new Houses<T>(count, defaultValue);
    }
}

调用的例子：

Example of calling:

Houses<string> x = Houses.CreateFromDefault(10, "hi");
Houses<int> y = Houses.CreateFromElements(20, 30, 40);

那么你的泛型类型的构造并不需要PARAMS位，并且将没有混乱。

Then your generic type's constructor doesn't need the "params" bit, and there'll be no confusion.

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