c# - 如何将接口(interface)实现为 protected 方法？

Question

我偶然发现了 IController 并注意到它有一个方法 Execute。我的问题是，鉴于 Controller 派生自实现接口(interface) IController 的 ControllerBase，ControllerBase 是如何能够将 Execute 实现为 protected virtual?

我的理解是接口(interface)必须作为公共(public)方法来实现。我对此的理解更加复杂，因为您不能在实例化的 Controller 上调用 Execute，而必须将其转换为 IController 的实例.

如何将接口(interface)实现为 protected 方法？

补充一点，我知道显式接口(interface)实现，但是如果你 view the source code对于 ControllerBase，您会看到该方法实现为 protected virtual void Execute(RequestContext requestContext)

Answer 1

它被称为显式接口(interface)实现。

A class that implements an interface can explicitly implement a member of that interface. When a member is explicitly implemented, it cannot be accessed through a class instance, but only through an instance of the interface.

在 MSDN 上阅读更多信息:Explicit Interface Implementation Tutorial .

简单示例:

interface IControl
{
    void Paint();
}

public class SampleClass : IControl
{
    void IControl.Paint()
    {
        System.Console.WriteLine("IControl.Paint");
    }

    protected void Paint()
    {
        // you can declare that one, because IControl.Paint is already fulfilled.
    }
}

和用法:

var instance = new SampleClass();

// can't do that:
// instance.Paint();

// but can do that:
((IControl)instance).Paint();