c++ - 从向量中读回数据时出错

Question

这是我从文本文件中读取数据并将其存储到向量中的程序，我在编译时遇到了麻烦，任何建议都会很棒。我喜欢在这个例子中调用年和月的所有数据。我希望它是我错过的一些简单的东西。

#include <iostream>
#include <libscat.h>
#include <fstream>
#include <sstream>
#include <vector>
#include <string>

struct Weather
{
  int year;
  int month;
  double tempmax;
  double tempmin;

};

int main()
{
  vector<Weather> data_weather;
  string line;
  std::ifstream myfile ("weatherdata.txt");
  if (myfile.is_open())
  {
    while ( getline(myfile, line) )
    {   int count = 0;
        if (count > 8) 
        {
            std::istringstream buffer(line);
            int year, mm;
            double tmax, tmin;
            if (buffer >> year >> mm >> tmax >> tmin) 
            {
            Weather objName = {year, mm, tmax, tmin};
            data_weather.push_back(objName);
            count++;
            }
        }

        for (auto it = data_weather.begin(); it != data_weather.end(); it++){ 
        std::cout << it->year << " " << it->month << std::endl;}
        myfile.close();
    }
    else
    {
    cout << "unable to open file";
    }
    scat::pause("\nPress <ENTER> to end the program.");

    return 0;
  }
}

Answer 1

这是一个带有解释的固定版本，因为仍然没有任何真正的答案。

#include <iostream>
#include <libscat.h>
#include <fstream>
#include <sstream>
#include <vector>
#include <string>

struct Weather
{
    int year;
    int month;
    double tempmax;
    double tempmin;
};

int main()
{
    std::vector<Weather> data_weather;
    std::string line;
    std::ifstream myfile("weatherdata.txt");
    if (myfile.is_open())
    {
        int count = 0;  // you gotta put it in front of the while loop or you'll
                // create a new variable and initialize it to 0 every time
                // you enter the loop
        while ( getline(myfile, line) )
        {
            // int count = 0; // placed it just before the loop
            if ( count > 8)
            {
                std::istringstream buffer(line);
                int year, mm;
                double tmax, tmin;
                if (buffer >> year >> mm >> tmax >> tmin)
                {
                    Weather objName = {year, mm, tmax, tmin};
                    data_weather.push_back(objName);
                    // count++; // you're still inside the if (count > 8)
                    // you'd probably want to have it outsided the if statement
                    // instead.
                }
            }
            ++count;    //the count from inside. it'll probably do what you wanted
                    //it to do here.

            // you'll probably want to run the for loop AFTER the while loop
            // when the data_weather vector got fully filled
        }
        // the for loop from inside the while now outside
        for (auto it = data_weather.begin(); it != data_weather.end(); ++it)
        {
            std::cout << it->year << " " << it->month << std::endl;
            myfile.close();
        }
    }
    else
    {
        std::cout << "unable to open file";
    }
    scat::pause("\nPress <Enter> to end the program.");
    return 0;
}