根据类型参数创建对象 [英] Creating an object based on a type parameter

问题描述

我有一个问题要摆在我面前.我有一个方法CreateInternals()的类A. CreateInternals()任务之一是创建一个新的B对象. B对象有几种类别(B1，B2，B3 ...)，但是它们都实现了接口IBable.应该将要创建的B对象的类型传递给A.CreateInternals().
现在我知道我可以让CreateInternals接受System.Type参数

I am having a problem bending my mind to situation. I have a class A with a method CreateInternals(). One of CreateInternals() tasks is to create a new B-object. There are several classes of B-object (B1, B2, B3...) but they all implement the interface IBable. The type of B object to be created is supposed to be passed to A.CreateInternals().
Now I know that I could just have CreateInternals accept a System.Type parameter

public void CreateInternals(System.Type BToMake)
{
	ConstructorInfo cInfo = type.GetConstructor(argTypes);
	IBable internalB = (IBable)cInfo.Invoke(new object[]());
	...
}

并以适当的类型进行调用

and call it with the appropriate type

A.CreateInternals(typeof(B2));

但是，这不会阻止我用无效的类型
调用CreateInternals

However, this would not prevent me from calling CreateInternals with an invalid type

A.CreateInternals(typeof(C));

而且直到运行时我都看不到错误.

有没有办法让编译器限制CreateInternals 仅接受实现IBable的BToMake 参数?像

and I would not see the error until runtime.

Is there a way to get the compiler to restrict CreateInternals to only accept BToMake parameters that implement IBable? Something like

public voide CreateInternals(System.Type BToMake where BToMake is IBable) {...}

我有一种奇怪的感觉，我可以使用泛型来做到这一点，但是我想我一直盯着这个问题已经很长时间了，以至于我已经绞尽脑汁，答案就不会出现.

任何帮助将不胜感激.

I have the strange feeling that I can do this using generics, but I think I''ve been staring at the problem for so long that I have brain-lock and the answer just won''t come.

Any help would be appreciated.

推荐答案

2种方法.如果您不想将对象的实例作为参数处理:

2 ways of doing it. If you prefer NOT having to deal with instances of your object as parameters:

public void CreateInternals<T>() where T:IBable
{
    Type theTypeIs = typeof(T);
..
..
..
}

CreateInternals<yourclassname>();
</yourclassname>

否则，如果您希望将实例作为参数传递:

Otherwise, if you prefer passing instances as parameters:

public static void CreateInternals<T>(T BToMake ) where T:IBable
{
    Type theTypeIs = BToMake.GetType();
..
..
..
}

CreateInternals(someInstanceImplementingYourInterfaceIBable);

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