在C 中，如何将其作为成员变量构建数据结构
In c++, how do I build a data structure with objects as member variables?
我最近开始研究，该研究涉及我完全不熟悉的CPP编码，并且遇到了很多东西：
- 默认构造函数
- 以对象作为成员变量创建数据结构。
我的程序设置需要这样：
- 我需要创建一个具有其成员变量之一的数据结构，作为Wave对象的数组：Wave []
- 实际上是从波浪文件中读取波浪的(我的代码链接到某些外部库来执行此操作(
- 每个波都有一个GPS对象。
- 每个GPS对象都有〜15个成员变量INT类型或double
这就是我的GPS.HPP课程的样子 -
#ifndef GPS_HPP_
#define GPS_HPP_
#include <iostream>
#include <fstream>
#include "pulsereader.hpp"
#include "pulsewriter.hpp"
class GPS{
public:
//possible parameters
double gpsTime;
double xAnchor, yAnchor, zAnchor;
double xTarget, yTarget, zTarget;
double xDeviation, yDeviation, zDeviation;
double xFirst, yFirst, zFirst;
double xLast, yLast, zLast;
unsigned char edge;
unsigned char facet;
unsigned char scanDirection;
unsigned char intensity;
PULSEreadOpener pOpener;
PULSEreader *pReader;
PULSEscanner scanner;
GPS();
void setGPSInformation();
void writeToFileGPSInformation(std::string fileName);
};
#endif /* GPS_HPP_ */
This is my GPS.cpp class:
#include <iostream>
#include "GPS.hpp"
//Default constructor
GPS::GPS(){
// enter default values
xAnchor = 0;
yAnchor = 0;
zAnchor = 0;
xTarget = 0;
yTarget = 0;
zTarget = 0;
xFirst = 0;
yFirst = 0;
zFirst = 0;
xLast = 0;
yLast = 0;
zLast = 0;
edge = 0;
facet = 0;
scanDirection = 0;
intensity = 0;
}
void GPS::setGPSInformation(){
gpsTime = pReader->pulse.get_t();
// Compute anchor, target and direction
pReader->pulse.compute_anchor_and_target_and_dir();
xAnchor = pReader->pulse.get_anchor_x();
yAnchor = pReader->pulse.get_anchor_y();
zAnchor = pReader->pulse.get_anchor_z();
xTarget = pReader->pulse.get_target_x();
yTarget = pReader->pulse.get_target_y();
zTarget = pReader->pulse.get_target_z();
// Compute first and last returning Values
pReader->pulse.compute_first_and_last();
xFirst = pReader->pulse.get_first_x();
yFirst = pReader->pulse.get_first_y();
zFirst = pReader->pulse.get_first_z();
xLast = pReader->pulse.get_last_x();
yLast = pReader->pulse.get_last_y();
zLast = pReader->pulse.get_last_z();
edge = pReader->pulse.edge_of_scan_line;
scanDirection = pReader->pulse.scan_direction;
facet = pReader->pulse.mirror_facet,
intensity = pReader->pulse.intensity;
}
/*
* Writes all GPS information to a csv file
*/
void GPS::writeToFileGPSInformation(std::string fileName){
long long pulseIndex = 0;
FILE *scanout;
scanout = fopen("gps.csv", "w");
fprintf(scanout, "Pulse Index, GPS Time, X Anchor, Y Anchor, Z Anchor,
X Target, Y Target, Z Target, X First,
Y First, Z First, X Last, Y Last, Z Last,
edge, Scan Direction, facet, intensityn");
pOpener.set_file_name(fileName.c_str());
pReader = pOpener.open();
pReader->seek(0);
while(pReader->read_pulse()) {
gpsTime = pReader->pulse.get_t();
pReader->pulse.compute_anchor_and_target_and_dir();
xAnchor = pReader->pulse.get_anchor_x();
yAnchor = pReader->pulse.get_anchor_y();
zAnchor = pReader->pulse.get_anchor_z();
xTarget = pReader->pulse.get_target_x();
yTarget = pReader->pulse.get_target_y();
zTarget = pReader->pulse.get_target_z();
pReader->pulse.compute_first_and_last();
xFirst = pReader->pulse.get_first_x();
yFirst = pReader->pulse.get_first_y();
zFirst = pReader->pulse.get_first_z();
xLast = pReader->pulse.get_last_x();
yLast = pReader->pulse.get_last_y();
zLast = pReader->pulse.get_last_z();
edge = pReader->pulse.edge_of_scan_line;
scanDirection = pReader->pulse.scan_direction;
facet = pReader->pulse.mirror_facet,
intensity = pReader->pulse.intensity;
fprintf(scanout, "%lld,%.8lf,
%lf,%lf,%lf,
%lf,%lf,%lf,
%lf,%lf,%lf,
%lf,%lf, %lf,
%d,%d,%d,%d,n",
pulseIndex, gpsTime,
xAnchor, yAnchor, zAnchor,
xTarget, yTarget, zTarget,
xFirst, yFirst, zFirst,
xLast, yLast, zLast,
edge, scanDirection, facet, intensity) ;
pulseIndex++;
}
}
这是我的gps.cpp：
#include <iostream>
#include "GPS.hpp"
//Default constructor
GPS::GPS(){
// enter default values
xAnchor = 0;
yAnchor = 0;
zAnchor = 0;
xTarget = 0;
yTarget = 0;
zTarget = 0;
xFirst = 0;
yFirst = 0;
zFirst = 0;
xLast = 0;
yLast = 0;
zLast = 0;
edge = 0;
facet = 0;
scanDirection = 0;
intensity = 0;
}
void GPS::setGPSInformation(){
gpsTime = pReader->pulse.get_t();
// Compute anchor, target and direction
pReader->pulse.compute_anchor_and_target_and_dir();
xAnchor = pReader->pulse.get_anchor_x();
yAnchor = pReader->pulse.get_anchor_y();
zAnchor = pReader->pulse.get_anchor_z();
xTarget = pReader->pulse.get_target_x();
yTarget = pReader->pulse.get_target_y();
zTarget = pReader->pulse.get_target_z();
// Compute first and last returning Values
pReader->pulse.compute_first_and_last();
xFirst = pReader->pulse.get_first_x();
yFirst = pReader->pulse.get_first_y();
zFirst = pReader->pulse.get_first_z();
xLast = pReader->pulse.get_last_x();
yLast = pReader->pulse.get_last_y();
zLast = pReader->pulse.get_last_z();
edge = pReader->pulse.edge_of_scan_line;
scanDirection = pReader->pulse.scan_direction;
facet = pReader->pulse.mirror_facet,
intensity = pReader->pulse.intensity;
}
/*
* Writes all GPS information to a csv file
*/
void GPS::writeToFileGPSInformation(std::string fileName){
long long pulseIndex = 0;
FILE *scanout;
scanout = fopen("gps.csv", "w");
fprintf(scanout, "Pulse Index, GPS Time, X Anchor, Y Anchor, Z Anchor,
X Target, Y Target, Z Target, X First,
Y First, Z First, X Last, Y Last, Z Last,
edge, Scan Direction, facet, intensityn");
pOpener.set_file_name(fileName.c_str());
pReader = pOpener.open();
pReader->seek(0);
while(pReader->read_pulse()) {
gpsTime = pReader->pulse.get_t();
pReader->pulse.compute_anchor_and_target_and_dir();
xAnchor = pReader->pulse.get_anchor_x();
yAnchor = pReader->pulse.get_anchor_y();
zAnchor = pReader->pulse.get_anchor_z();
xTarget = pReader->pulse.get_target_x();
yTarget = pReader->pulse.get_target_y();
zTarget = pReader->pulse.get_target_z();
pReader->pulse.compute_first_and_last();
xFirst = pReader->pulse.get_first_x();
yFirst = pReader->pulse.get_first_y();
zFirst = pReader->pulse.get_first_z();
xLast = pReader->pulse.get_last_x();
yLast = pReader->pulse.get_last_y();
zLast = pReader->pulse.get_last_z();
edge = pReader->pulse.edge_of_scan_line;
scanDirection = pReader->pulse.scan_direction;
facet = pReader->pulse.mirror_facet,
intensity = pReader->pulse.intensity;
fprintf(scanout, "%lld,%.8lf,
%lf,%lf,%lf,
%lf,%lf,%lf,
%lf,%lf,%lf,
%lf,%lf, %lf,
%d,%d,%d,%d,n",
pulseIndex, gpsTime,
xAnchor, yAnchor, zAnchor,
xTarget, yTarget, zTarget,
xFirst, yFirst, zFirst,
xLast, yLast, zLast,
edge, scanDirection, facet, intensity) ;
pulseIndex++;
}
}
这是我目前用来将GPS信息写入CSV的驱动程序类。
#include <iostream>
#include "CmdLine.hpp"
#include "ScannerInformation.hpp"
#include "GPS.hpp"
using namespace std;
int main (int argc, char *argv[]){
CmdLine cmdLineArgs;
cmdLineArgs.parse(argc,argv);
if(cmdLineArgs.printUsageMessage == true){
std::cout << cmdLineArgs.getUsageMessage() << std::endl;
}
else{
std::string fileName = cmdLineArgs.getInputFileName();
ScannerInformation scannerInfo;
scannerInfo.writeToFileScannerInformation(fileName);
GPS gpsInfo;
gpsInfo.writeToFileGPSInformation(fileName);
}
return 0;
}
除了将GPS信息写入CSV之外，我还希望能够访问我的驱动程序类中的每个浪潮的GPS信息(类似于此( -
std::cout << wave.gpsInfo.xAnchor;
如何编写Wave.HPP和CPP，以使其具有GPS对象作为其成员变量，然后如何从驱动程序文件中访问Wave对象的GPS信息？
#include "GPS.hpp"
class Wave {
private:
GPS gps;
public:
//What kind of methods would I use here?
};
我要回答标题。
您只是这样做！一个例子：
struct Pos
{
int x = 0;
int y = 0;
};
struct Line
{
Pos start;
Pos end;
};
一些笔记：
-
Pos和Line都是类。不要让关键字struct欺骗您。由于都没有类不变，因此他们的数据可以公开。 - 除非您必须编写构造函数。可以在课堂上完成成员的初始化。
- C 具有价值语义；这意味着类型通常行为像int一样，没有特殊的处理来区分对象和其他类型。
沿线的东西：
#include "GPS.hpp"
#include "OutgoingWave.hpp"
#include "IncomingWave.hpp"
class Wave {
private:
GPS _gps;
OutgoingWave _ow;
IncomingWave _iw;
public:
const GPS& gps() const { return _gps; }
const OutgoingWave& ow() const { return _ow; }
const IncomingWave& iw() const { return _iw; }
};
确保返回的引用不会超过Wave对象(如果是这样，则返回值，但会产生其他复制(。GPS，IncomingWave和OutgoingWave类可以转换为struct S，以便默认公开访问所有成员。顺便说一句，您发布的代码不编译，public和private修饰符需要在类中。
要准确获取您在问题中要求的代码，您需要公开提供会员。最好使用一个结构来完成，因为默认情况下它是公开的。
struct Wave {
GPS gpsInfo;
};
struct GPS {
double gpsTime;
double xAnchor; //you may want to use a Point class or struct
...
unsigned char intensity;
};
这样，您就不需要任何额外的方法(即Getters and Setters(。这种方法没有错，但是您基本上失去了添加诸如SANITY检查输入的功能的可能性。如果Wave或GPS具有更复杂的状态，并且成员依赖于彼此的值，则可能需要使用类并使用Getters和Setters封装对成员的访问。
相关文章：
- 将成员变量添加到共享库中的类中，不会破坏二进制兼容性吗
- 具有奇怪重复模板模式的派生类中的成员变量已损坏
- 内置函数可查看CPP中的成员变量
- 是否可以初始化不可复制类型的成员变量(或基类）
- 将包含C样式数组的对象初始化为成员变量(C++）
- 为什么我不能在一个类的不同行中声明和定义成员变量？
- 在循环中按顺序遍历成员变量
- c++类声明时，相同的例程，不同的成员变量类型
- 如何从另一个文件继承私有成员变量和公共函数
- 在C++类中，是否必须初始化作为数组的成员变量
- 如何从子成员函数修改父公共成员变量
- 我可以在 C++ 中将数据成员/变量从其定义之外添加到结构中吗?
- 从私有成员变量的成员方法返回unique_ptr
- 在派生类中使用基类的私有成员变量的最佳方法
- 静态 constexpr 类成员变量对多线程读取是否安全?
- C++:是否可以使用非静态成员变量模板?
- 打印所有继承的类成员变量和方法
- 如何在复杂继承中访问静态成员变量
- 为什么我不能在返回 const 的布尔函数中为类成员变量赋值？C++
- 成员变量与函数概念检查
