CA1047'使成员引发private，public或internal'和C ++ / CLI事件 [英] CA1047 'Make member raise private, public, or internal' and C++/CLI events

问题描述

当我在密封的C ++ / CLI类中声明公共事件时，我会收到代码分析警告CA1047。该警告似乎来自自动生成的受保护成员函数。如何解决此警告？

When I declare a public event in a sealed C++/CLI class, I get Code Analysis warning CA1047. The warning seems to come from auto-generated protected member functions. How can I fix this warning?

这里有一个例子。此代码

Here's an example. This code

ref class Test sealed {
public:
    event EventHandler^ blah;
};

产生：

警告：CA1047：Microsoft.Design：使成员'Test :: blah :: raise（Object ^，EventArgs ^）'private，public或internal

warning: CA1047 : Microsoft.Design : Make member 'Test::blah::raise(Object^, EventArgs^)' private, public, or internal

推荐答案

我会更好地记录这个问题。此代码

I'll document the question better. This code

ref class Test sealed {
public:
    event EventHandler^ blah;
};

产生：

警告：CA1047：Microsoft.Design：使成员'Test :: blah :: raise（Object ^，EventArgs ^）'private，public或internal

warning: CA1047 : Microsoft.Design : Make member 'Test::blah::raise(Object^, EventArgs^)' private, public, or internal

是的，当你不自己指定事件访问器时，编译器会为你生成它们。它会自动生成add，remove和raise访问器。后者看起来像这样当你看看ildasm.exe：

Yes, when you don't specify the event accessors yourself then the compiler will generate them for you. It auto-generates the add, remove and raise accessors. The latter one looks like this when you look with ildasm.exe:

.method family hidebysig specialname instance void 
        raise_blah(object value0,
                   class [mscorlib]System.EventArgs value1) cil managed
{
    // etc..
}

family 属性是导致代码分析警告的原因。自动生成的添加和删除访问者当然是公开的。自己写它是一个有问题的解决方法，你真的只想这样做，如果你有一个真正的理由来实现自定义访问器。样板版本如下：

The family attribute is what causes the code analysis warning. The auto-generated add and remove accessors are of course public. Writing them yourself is a questionable workaround, you really only want to do this if you have a real reason to implement custom accessors. The boilerplate version would look like this:

using namespace System::Runtime::CompilerServices;

ref class Test sealed {
private:
    EventHandler^ foo;
public:
    event EventHandler^ blah {
        [MethodImpl(MethodImplOptions::Synchronized)]
        void add(EventHandler^ d) { foo += d; }
        [MethodImpl(MethodImplOptions::Synchronized)]
        void remove(EventHandler^ d) { foo -= d; }
    private:
        void raise(Object^ sender, EventArgs^ e) { 
            EventHandler^ handler = foo;
            if (handler != nullptr) handler(sender, e);
        };
    }
};

那么，这当然会抑制警告。我建议你使用[SuppressMessage]属性，如果这不旋转你的螺旋桨。

Well, that certainly suppresses the warning. I recommend you use the [SuppressMessage] attribute if that doesn't spin your propeller.

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