Question

我不明白为什么编译器认为PERSON不是ref类：

：错误C2811：'跑步者'：不能继承自'Person'，ref类可以只从遗传类或继承接口类

我试过......

将mscorlib.dll添加到头文件中：#using..etc ...＆lt;＆gt; - 没用。
使Person成为一个抽象类 - 没有用（我很高兴，因为我想这是一个可实例化的类）

我先列出两个头文件。如果你需要，他们的cose会在后面列出。

PERSON.H

#pragma once
using namespace System;

ref class Person
{
private:
    void copy_ptr_data(Person%);
    void delete_ptr_data(void);
public:
    property String^ Name;
    property String^ Age;

    Person(String^ name, String^ age);
    Person(Person%);
    Person% operator= (Person%);
    bool operator==(Person%);
    bool operator!=(Person%);
    virtual ~Person(void); 
};

RUNNER.H

#pragma once
#include "Person.h"

using namespace System;

ref class Runner : public Person
{
private:
    void copy_ptr_data(Runner%);
    void delete_ptr_data(void);
public:
    property String^ Time;
    property String^ Rank;

    Runner(String^ name, String^ age, String^ time);
    Runner(Runner%);
    Runner% operator= (Runner%);
    bool operator==(Runner%);
    bool operator!=(Runner%);
    ~Runner(void);
};

PERSON.CPP

#include "StdAfx.h"
#include "Person.h"

Person::Person(String^ name, String^ age) 
{
    Name = name;
    Age = age; 
}

Person::Person(Person% p)
{
    Name = p.Name;
    Age = p.Age;

    copy_ptr_data(p);
}

Person% Person::operator= (Person% p)
{
    // prevent self-assignment
    if (this == %p) {
        return *this;
    }

    // deallocate/reallocate/assign dynamic memory
    delete_ptr_data();
    copy_ptr_data(p);

    // assign non-dynamic memory
    Name    = p.Name;
    Age     = p.Age;
    return *this;
}

bool Person::operator==(Person% p)
{
    if ((Name == p.Name) &&
        (Age == p.Age))
        return 1;

    return 0; 
}

bool Person::operator!=(Person% p)
{
return !(Person::operator==(p));
}

Person::~Person(void) 
{
    delete_ptr_data();
}

void Person::copy_ptr_data(Person% p)
{
    return;
}

void Person::delete_ptr_data()
{
    return;
}

RUNNER.CPP

#include "StdAfx.h"
#include "Runner.h"

Runner::Runner(String^ name, String^ age, String^ time) : Person(name, age)         
{
    Time = time;
    Rank = nullptr;     
}

Runner::Runner(Runner% r) : Person(r) 
{
    Time = r.Time;
    Time = r.Rank;

    copy_ptr_data(r);
}

Runner% Runner::operator= (Runner% r)
{ 
    // handle self assignment
    if (this == %r) return *this;

    // handle base class portion
    Person::operator=(r);      

    // handle dynamic portion
    delete_ptr_data();
    copy_ptr_data(r);

    // handle non-dynamic portion
    Time    = r.Time;
    Rank    = r.Rank;

    return *this;
}

bool Runner::operator==(Runner% r)
{
    if ((Person::operator==(r)) &&
        (Time == r.Time)        &&
        (Rank == r.Rank))
        return 1;

    return 0; 
}

bool Runner::operator!=(Runner% r)
{
return !(Runner::operator==(r));
}

Runner::~Runner(void) 
{
}

void Runner::copy_ptr_data(Runner% r)
{
    return;
}


void Runner::delete_ptr_data()
{
    return;
}

Answer 1

你不应该放：

#using <mscorlib.dll>

位于头文件的顶部？我不确定这是不是可以解决这个问题。

尝试制作Person班abstract。

为什么PERSON不是ref级？

1 个答案: