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

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.

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。

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。

Internal表示只能从同一程序集中访问成员。该程序集中的其他类可以访问内部公共成员,但不能访问私有成员或受保护成员(无论是否是内部成员)。

我今天真的很纠结这个问题。到目前为止,如果类是内部的,我会说方法都应该被标记为内部的,并且会认为其他任何东西都只是糟糕的编码或懒惰,特别是在企业开发中;然而,我必须子类化一个公共类并重写它的一个方法:

internal class SslStreamEx : System.Net.Security.SslStream
{
    public override void Close()
    {
        try
        {
            // Send close_notify manually
        }
        finally
        {
            base.Close();
        }
    }
}

方法必须是公共的,这让我想到,将方法设置为内部没有逻辑意义,除非它们真的必须是,就像Eric Lippert说的那样。

直到现在,我从来没有真正停下来思考过这个问题,我只是接受了它,但在阅读了Eric的帖子后,它真的让我思考,经过很多深思熟虑后,它有很多意义。