无法将指向 class 的成员函数的函数指针作为参数传递给同一 class 的另一个成员函数

Question

我需要帮助...评论中提出了适当的问题。程序的编译器错误和警告为零！！我担心使用函数指针从另一个成员函数调用成员函数。（准确地说，setMatrixto() 试图使用函数指针调用 setElement() 函数）

另外，"hello there" 没有被打印到控制台。我期待它显示为 output.Maybe setMatrixto() 根本没有被调用！！

头文件定义

#ifndef MATRIXOPERATIONS_H
#define MATRIXOPERATIONS_H

class MatrixOperations;

typedef int (MatrixOperations::*INTFUNC)(int,int);
typedef void (MatrixOperations::*VOIDFUNC)(int,int,int);

class MatrixOperations
{
    public:
        MatrixOperations();
        MatrixOperations(int size);
        ~MatrixOperations();

        //diagonal matrix funtions
        void displayMatrixOf(INTFUNC f);
        void setMatrixTo(VOIDFUNC f);

        int getElement(INTFUNC from, int i, int j);
        void setElement(VOIDFUNC to,int i ,int j, int value);

        int fromDiagonalArray(int i, int j);
        void toDiagonalArray(int i, int j, int value);
    protected:

    private:
        int size;
        int* a;

};



#endif // MATRIXOPERATIONS_H

CPP 实施文件

#include "MatrixOperations.h"
#include <iostream>
using namespace std;


MatrixOperations::MatrixOperations()
{
    //ctor
    size = 3;
    a = new int[size];



}
MatrixOperations::MatrixOperations(int size)
{
    //ctor
    this->size = size;
    a = new int[size];


}


MatrixOperations::~MatrixOperations()
{
    //dtor
    delete[] a;
}




///////////////////FUCNTION POINTER SECTION///////////////////////////////////
int MatrixOperations::getElement(INTFUNC from, int i, int j)
{
    return (this->*from)(i,j);

}

void MatrixOperations::setElement(VOIDFUNC to,int i ,int j, int value)
{

    (this->*to)(i,j,value);
}




/////////////////////////////////DIAGONAL ARRAY OPERATIONS/////////////////////////////////////////////////
int MatrixOperations::fromDiagonalArray(int i, int j)
{
    if(i==j)
    {
        return a[i];
    }
    else
    {
        return 0;

    }
}
void MatrixOperations::toDiagonalArray(int i, int j, int value)
{
    a[i] = value;
}

///////////////////////////////////////////////////////////////////
void MatrixOperations::displayMatrixOf(INTFUNC f)
{
    for(int i{0}; i < size; i++)
    {
        for(int j{0}; j < size; j++)
        {
            cout << getElement(f,i,j) << "\t"; //is this the correct way to send the function pointer?
        }
        cout << endl;
    }

}

void MatrixOperations::setMatrixTo(VOIDFUNC f)
{
    cout << "Hello there!!";                      //not getting this output.. whats wrong??
    for(int i{0}; i < size; i++)
    {


            int value {};
            cout << "Enter value diagonal element " << i << " : ";
            cin >> value;
            setElement(f,i,i,value);             //is this the correct way to send the function pointer?

    }

}
///////////////////////////////////////////////////////////////////////////////

主文件

#include <iostream>
#include "MatrixOperations.h"

typedef MatrixOperations MATRIX;


using namespace std;

int main()
{
    MATRIX m1;

    m1.setMatrixTo(MATRIX::toDiagonalArray); //was expecting a "Hello there!" but i am not getting that output either
    return 0;
}

EDIT2：我在一个文件中添加了所有 class 定义和主要功能。出奇！！这行得通。我糊涂了？？！！！

#include <iostream>

using namespace std;

class MatrixOperations;

typedef void (MatrixOperations::*VOIDFUNC)(int,int,int);
typedef MatrixOperations MATRIX;

class MatrixOperations
{
    public:
        MatrixOperations();
        MatrixOperations(int size);
        ~MatrixOperations();


        //diagonal matrix funtions

        void setMatrixTo(VOIDFUNC f);
        void setElement(VOIDFUNC to,int i ,int j, int value);
        void toDiagonalArray(int i, int j, int value);
    private:
        int size;
        int* a;

};
MatrixOperations::MatrixOperations()
{    //ctor
    size = 3;
    a = new int[size];
}
MatrixOperations::MatrixOperations(int size)
{    //ctor
    this->size = size;
    a = new int[size];
}
MatrixOperations::~MatrixOperations()
{
    //dtor
    delete[] a;
}
void MatrixOperations::setElement(VOIDFUNC to,int i ,int j, int value)
{

    (this->*to)(i,j,value);
}




/////////////////////////////////DIAGONAL ARRAY OPERATIONS/////////////////////////////////////////////////
void MatrixOperations::toDiagonalArray(int i, int j, int value)
{
    a[i] = value;
}

///////////////////////////////////////////////////////////////////
void MatrixOperations::setMatrixTo(VOIDFUNC f)
{
    cout << "Hello there!!" << endl;
    for(int i{0}; i < size; i++)
    {


            int value {};
            cout << "Enter value diagonal element " << i << " : ";
            cin >> value;
            setElement(f,i,i,value);

    }

}

int main()
{

    MATRIX m1;

    m1.setMatrixTo(MATRIX::toDiagonalArray);
    return 0;
}

Answer 1

两种情况下的代码都没有问题。它只是我的调试器不是运行在管理模式下。我收到错误代码 740。所以我在管理员模式下启动了我的 IDE，瞧，它成功了。

无法将指向 class 的成员函数的函数指针作为参数传递给同一 class 的另一个成员函数

Unable to pass a function pointer to a member function of the class as an argument to another member function of the same class

c++

function-pointers

member-function-pointers