我发现自己最近更经常地使用显式实现，原因如下:

Always using explicit from the starts prevents having any naming collisions, in which explicit implementation would be required anyways Consumers are "forced" to use the interface instead of the implementation (aka not "programming to an implementation") which they should / must do anyways when you're using DI No "zombie" members in the implementations - removing any member from the interface declaration will result in compiler errors if not removed from the implementation too Default values for optional parameters, as well constraints on generic arguments are automatically adopted - no need to write them twice and keep them in sync

隐式接口实现是指具有与接口相同签名的方法。

显式接口实现是显式声明方法属于哪个接口的地方。

interface I1
{
    void implicitExample();
}

interface I2
{
    void explicitExample();
}


class C : I1, I2
{
    void implicitExample()
    {
        Console.WriteLine("I1.implicitExample()");
    }


    void I2.explicitExample()
    {
        Console.WriteLine("I2.explicitExample()");
    }
}

MSDN:隐式和显式接口实现

隐式是指通过类上的成员定义接口。显式是指在接口上的类中定义方法。我知道这听起来令人困惑，但我的意思是:IList。CopyTo将隐式实现为:

public void CopyTo(Array array, int index)
{
    throw new NotImplementedException();
}

并明确为:

void ICollection.CopyTo(Array array, int index)
{
    throw new NotImplementedException();
}

不同之处在于，隐式实现允许您通过创建的类访问接口，方法是将接口转换为该类和接口本身。显式实现允许您仅通过将接口转换为接口本身来访问接口。

MyClass myClass = new MyClass(); // Declared as concrete class
myclass.CopyTo //invalid with explicit
((IList)myClass).CopyTo //valid with explicit.

我使用显式主要是为了保持实现的简洁，或者当我需要两个实现时。不管怎样，我很少使用它。

我相信有更多的理由使用/不使用explicit，其他人会发布。

请参阅本帖的下一篇文章，了解每一篇文章背后的优秀推理。

引用Jeffrey Richter从CLR通过c#编写的 (EIMI的意思是显式接口方法实现)

It is critically important for you to understand some ramifications that exist when using EIMIs. And because of these ramifications, you should try to avoid EIMIs as much as possible. Fortunately, generic interfaces help you avoid EIMIs quite a bit. But there may still be times when you will need to use them (such as implementing two interface methods with the same name and signature). Here are the big problems with EIMIs: There is no documentation explaining how a type specifically implements an EIMI method, and there is no Microsoft Visual Studio IntelliSense support. Value type instances are boxed when cast to an interface. An EIMI cannot be called by a derived type.

如果您使用接口引用，ANY虚链可以在任何派生类上显式地替换为EIMI，并且当这种类型的对象强制转换到接口时，您的虚链将被忽略，并调用显式实现。这根本不是多态性。

EIMIs还可以用于从基本框架接口的实现(如IEnumerable<T>)中隐藏非强类型接口成员，这样你的类就不会直接公开非强类型方法，但在语法上是正确的。

显式接口实现的一个重要用途是在需要实现具有混合可见性的接口时。

这个问题和解决方案在c#内部接口这篇文章中有很好的解释。

例如，如果您希望保护应用程序层之间对象的泄漏，该技术允许您指定可能导致泄漏的成员的不同可见性。

隐式定义是将接口需要的方法/属性等直接作为公共方法添加到类中。

显式定义强制只在直接使用接口而不是底层实现时才公开成员。在大多数情况下，这是首选。

By working directly with the interface, you are not acknowledging, and coupling your code to the underlying implementation. In the event that you already have, say, a public property Name in your code and you want to implement an interface that also has a Name property, doing it explicitly will keep the two separate. Even if they were doing the same thing I'd still delegate the explicit call to the Name property. You never know, you may want to change how Name works for the normal class and how Name, the interface property works later on. If you implement an interface implicitly then your class now exposes new behaviours that might only be relevant to a client of the interface and it means you aren't keeping your classes succinct enough (my opinion).