I get the error C3984 when I try to compile my C++ program

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When you move your class header over to a Windows Store app, you get an error might look like the following:

  • error C3984: 'Aliens' : a non-value type cannot have any public data members 'appendages'

The code looks like the following, and it worked in the console app you built:

using namespace System;

ref class Aliens
{
public:
    int appendages;

    void SetAlienName(String ^san)
    {
        AlienID=san;
    }
    String^ GetAlienID()
    {
        return AlienID;
    }

//The variable AlienID is private and requires that
// must be added to the other functions to manipulate the value of AlienID
private:
    String ^AlienID;
};

 

What happened and why isn’t it working? 

C++/CX doesn’t support public fields.

To fix: You can just make the line “int appendages; into a “trival property”.  The term “Trivial Properties” are like calling the cute adorable dolphin a common dolphin,  a trivial property is trivial because it is a single line of code, I guess, seems like a pretty cool way to do things.

Rewrite the “int appendages” to “property so your code will look like the following, for more examples check out the link: Properties (C++/CX)

image

Now your class will work in an App that is running C++/CX!  This is a more secure process.