Question

I am new to visual C++. I wrote my class, but it has error

Error 1 error C3845: ‘CRegistration::list1’: only static data members can be initialized inside a ref class or value type c:\users\marco\desktop\cs351\hw3\project3\CRegistration.h 44 1 Project3

I understand the compiler has said what the error is. However, I don’t understand what it means. The following is my code

#pragma once

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;
using namespace System::Collections;
using namespace System::Collections::Generic;


public ref class CRegistration
{
public: 

    CRegistration(void){

        ClickBoxRecord = 0;

        ClickBoxRecord = 0;


    };//end constructor

    void SetRadioRecord(int flag){ RadioRecordRecord = flag; }

    void SetClickBoxRecord(int flag){ ClickBoxRecord = flag; }

    int GetRadioRecordRecord(){return RadioRecordRecord}

    int GetClickBoxRecord(){return ClickBoxRecord}



protected:

private:

    int RadioRecordRecord;

    int ClickBoxRecord;

    LinkedList< int > list1 = gcnew LinkedList< int >();

    LinkedList< String^ > ^list2 = gcnew LinkedList< String^ >();

    LinkedList< String^ > ^list3 = gcnew LinkedList< String^ >();

    LinkedList< String^ > ^list4 = gcnew LinkedList< String^ >();

    LinkedList< String^ > ^list5 = gcnew LinkedList< String^ >();


};//end ref class

Answer 1

Are you trying to learn C++ or are you trying to learn CLI?

// native C++
#include <list>
#include <string>

std::list<int> list1;
std::list<double> list2;
std::list<std::string> list3;
std::list<std::string> list4;
std::list<std::string> list5;

P.S.

The problem is your inline initialization of non-static members list1 through list5. In C++ initialization of non-static members is done in an initializer list or the body of a constructor normally. In C++ we generally use the stack as much as possible and only use the heap when we have to as memory management is important.

// C++/CLI

// you can either make a list of each
LinkedList< int > list1;    // list of int
LinkedList< double > list2; // list of double
LinkedList< String > list3; // list of String

// or make an object that has one of each
public ref class AllThree {
    public:
       // members
       String str;
       double dbl;
       int i;
};

// and make a list of that object
LinkedList<AllThree> list4; // list of AllThree