Rules for references when inheriting from base class

Question

Given that Project A is a C# Class Library and that Project B is a console application that has a dependency on Project A.

In Project A the following class is defined:

public class ActionMailNotifier : RazorMailerBase
{
        private readonly string _viewPath;
        private readonly EmailHost _emailConfig;
                   ...
                   ...
}

"RazorMailBase" is contained in an external dll, ActionMailer.dll, that is referenced by Project A.

In Project B the following class is defined:

public class EmailFareMonitorAlertNotifier : ActionMailNotifier
{
                        ...
                        ...
}

If ActionMailer.dll is not referenced in Project B the compiler generates an error message indicating that a reference to ActionMailer.dll is required. Is there a way to structure this such that a reference to the external dll is not required in Project B?

Answer 1

EmailFareMonitorAlertNotifier只要EmailFareMonitorAlertNotifier最终从程序集external.dll派生，您需要引用它，以便编译器和运行时具有使用该类型所需的信息。

Answer 2

No. If you were to remove all references to any type in Project B that references ActionMailer.dll, you wouldn't see any errors. But since RazorMailBase is defined in ActionMailer.dll, you'll have to have that reference to use ActionMailNotifier , or any other type derived from a class in the external library.

Answer 3

作为绝对最小值，项目B将必须引用其自己类型的EmailFareMonitorAlertNotifier的继承层次结构中存在的所有程序集，所以我猜答案是否定的。