在我们的一个项目中，有很多代码看起来像这样:
internal static class Extensions
{
public static string AddFoo(this string s)
{
if (s == null)
{
return "Foo";
}
return $({s}Foo);
}
}
除了“以后更容易将类型公开”之外，还有其他明确的原因吗?
我怀疑它只在非常奇怪的边缘情况下(在Silverlight反射)或根本不重要。
当前回答
There does be a difference. In our project we have made a lot of classes internal, but we do unit test in another assembly and in our assembly info we used InternalsVisibleTo to allow the UnitTest assembly to call the internal classes. I've noticed if internal class has an internal constructor we are not able to create instance using Activator.CreateInstance in the unit test assembly for some reason. But if we change the constructor to public but class is still internal, it works fine. But I guess this is a very rare case (Like Eric said in the original post: Reflection).
其他回答
I often mark my methods in internal classes public instead of internal as a) it doesn't really matter and b) I use internal to indicate that the method is internal on purpose (there is some reason why I don't want to expose this method in a public class. Therefore, if I have an internal method I really have to understand the reason why it's internal before changing it to public whereas if I am dealing with a public method in an internal class I really have to think about why the class is internal as opposed to why each method is internal.
如果类是内部的，那么从可访问性的角度来看，将方法标记为内部的还是公共的并不重要。但是，如果类是公共的，那么使用您将使用的类型仍然是好的。
虽然有些人说，这使得从内部到公开的过渡更加容易。它也作为方法描述的一部分。内部方法通常被认为是不安全的，不受约束的访问，而公共方法被认为是(大多数)自由游戏。
通过像在公共类中那样使用内部类或公共类，可以确保您传达了预期的访问风格，同时也简化了将来使类成为公共类所需的工作。
There does be a difference. In our project we have made a lot of classes internal, but we do unit test in another assembly and in our assembly info we used InternalsVisibleTo to allow the UnitTest assembly to call the internal classes. I've noticed if internal class has an internal constructor we are not able to create instance using Activator.CreateInstance in the unit test assembly for some reason. But if we change the constructor to public but class is still internal, it works fine. But I guess this is a very rare case (Like Eric said in the original post: Reflection).
在某些情况下，也可能是内部类型实现了一个公共接口，这意味着在该接口上定义的任何方法仍然需要声明为公共。
它是一样的，public方法将被标记为内部的，因为它在内部类中，但它有一个优点(正如你所说)，如果你想将类标记为公共的，你必须修改更少的代码。
