向CArray添加数据会产生错误“无法访问在类'CObject'中声明的私有成员”

Question

I have a structure called PERSONS and then I have defined a type CTypedPtrArray<CPtrArray, PERSONS*> PersonsTable;

struct Persons { ... };
typedef CTypedPtrArray<CPtrArray, PERSONS*> PersonsTable;

Later in the code I try to make a PersonTable CArray :

void CArrayTesting()
{
    CArray<PersonsTable, PersonsTable> oCArr;
    oCArr.SetSize(3);
    PersonsTable perTableA;
    PersonsTable perTableB;
    PersonsTable perTableC;
    for (int i = 0; i < 10; i++)
    {
        if (i < 3)      addPerson(perTableA, i);
        else if (i < 8) addPerson(perTableB, i);
        else            addPerson(perTableC, i);
    }
    oCArr.Add(perTableA);
    oCArr.Add(perTableB);
    oCArr.Add(perTableC);
    for (int nArrCnt = 0; nArrCnt < oCArr.GetSize(); nArrCnt++)
        for (int i = 0; i < oCArr.ElementAt(nArrCnt).GetSize(); i++)
        {
            cout<<"Table "<< nArrCnt << " - " << oCArr.ElementAt(nArrCnt)[i]->nID << endl;
            delete oCArr.ElementAt(nArrCnt)[i];
        }
}

The addPerson() function adds data to PersonTable .

However, this causes an error during the compilation: cannot access private member declared in class 'CObject . The error appears to be related to oCArr.Add() , because it gets 'fixed' when I delete the respected rows.

Why does the error appear? How can I fix it? And how does CArray work?

Answer 1

The error boils down to class CPtrArray not defining a copy constructor, which your code uses when adding to oCArr . The compiler generated default copy constructor will try to call the copy constructor for CObject , which is declared private .

You should probably add the elements into oCArr directly, rather than adding them to local variables then making copies.

Answer 2

1201 is correct, and it's a massive headache. If you're forced to use the MFC collections, you could derive from them and create custom copy constructors/assignment operators. (and move + initializer_list) The array collections have a Copy function you can use to make life simple.

class CPtrArrayEx : public CPtrArray
{
public:
    CPtrArrayEx() = default;
    CPtrArrayEx(CPtrArrayEx const& rhs)
    {
        Copy(rhs);
    }

    CPtrArrayEx& operator=(CPtrArrayEx const& rhs)
    {
        if (this != &rhs)
            Copy(rhs);
        return *this;
    }
};