怎么用VS2017敲出课程上的代码会报错啊？？

Question

coordiante.hclass coordinate{public:coordinate(int x, int y);~coordinate();int getx();int gety();public:int m_ix;int m_iy;};coordinate.cpp#include"coordinate.h"#include<iostream>using namespace std;coordinate::coordinate(int x, int y){m_ix = x;m_iy = y;cout << "(" << m_ix << "," << m_iy << ")" << endl;}coordinate::~coordinate(){cout << "我是析构函数" << endl;}int coordinate::getx(){return m_ix;}line.h#include"coordinate.h"class line{line(int x1, int y1, int x2, int y2);~line();void printinfo();private:coordinate *m_pcoora;coordinate *m_pcoorb;};line.cpp#include"line.h"#include<iostream>using namespace std;line::line(int x1, int y1, int x2, int y2){m_pcoora = new coordinate(x1, y1);m_pcoorb = new coordinate(x2, y2);cout << "line" << endl;}line::~line(){delete m_pcoora;m_pcoora = NULL;delete m_pcoorb;m_pcoorb = NULL;cout << "~line" << endl;}void line::printinfo(){cout << "(" << m_pcoora->getx() << "," << m_pcoora->gety() << ")" << endl;cout << "(" << m_pcoorb->getx() << "," << m_pcoorb->gety << ")" << endl;}main.cpp#include<iostream>#include"line.h"using namespace std;int main(){line *p = new line(1, 2, 3, 4);delete p;p = NULL;system("pause");return 0;}出现的错误：严重性 代码 说明 项目 文件 行 禁止显示状态错误(活动) E0330 "line::line(int x1, int y1, int x2, int y2)" (已声明 所在行数:6，所属文件:"E:\VS-c++\thispoint\thispoint\line.h") 不可访问 thispoint E:\VS-c++\thispoint\thispoint\main.cpp 8严重性 代码 说明 项目 文件 行 禁止显示状态错误(活动) E0330 "line::~line()" (已声明 所在行数:7，所属文件:"E:\VS-c++\thispoint\thispoint\line.h") 不可访问 thispoint E:\VS-c++\thispoint\thispoint\main.cpp 10严重性 代码 说明 项目 文件 行 禁止显示状态错误 C3867 “coordinate::gety”: 非标准语法；请使用 "&" 来创建指向成员的指针 thispoint e:\vs-c++\thispoint\thispoint\linecpp.cpp 25