fstream <无法读取内存>。无法打印列表中的所有项目

Question

我正在开发一个菜单驱动程序，让用户基本上可以跟踪他们的分配任务和截止日期。我的程序处理一个名为“tasks.txt”的文本文件，用户有 3 个选项用于与文本文件交互：输入新任务、显示文件中的所有任务或按课程查找任务。我的程序运行得相对不错，只是它似乎无法与文件完全交互。

下面是我的输出/输入文件：tasks.txt

CS162;Finish Project 2;04/10/2015
CS162;Finish Project 3;04/20/2015
CS162;Finish Project 4;05/10/2015
CS162;Finish Project 5;05/20/2015

这是我的代码：

#define _CRT_SECURE_NO_WARNINGS
#include <cstring>
#include <fstream>
#include <iostream>

using namespace std;

//Global constants
const int CAP = 100;
const int MAXCHAR = 201; // Task description can be a max of 200 characters in case its a long description (ie: specific instructions)

//Task struct
struct Task
{
    char courseName[MAXCHAR];
    char taskDescrip[MAXCHAR];
    char dueDate[MAXCHAR];
};

//function prototypes
void openFile(ifstream &inFile);
void loadData(ifstream &inFile, Task tasks[], int &listSize);
void exeCommand(char option, Task tasks[], int &listSize);
void displayMenu();
char readOption();
void getUserTask(Task &tempTask);
void addUserTask(Task tasks[], int &listSize, Task tempTask);
void printTasks(Task tasks[], const int listSize);
void writeFile(ofstream &outFile, Task tasks[], const int listSize);


//Main function
int main()
{
    int listSize = 0; //keep track of list size
    ofstream outFile; //output file stream variable
    ifstream inFile; //input file stream variable
    Task tasks[CAP]; //array of tasks
    char option; // user menu input for option
    openFile(inFile); //open up tasks.txt
    loadData(inFile, tasks, listSize); //load the data while in file into the array of tasks
    do
    {
        displayMenu();
        option = readOption();
        exeCommand(option, tasks, listSize);
    } while (tolower(option) != 'q');
    return 0;
}

//open the file
void openFile(ifstream &inFile)
{
    inFile.open("tasks.txt");
    if (!inFile)
    {
        cout << "file not open" << endl;
        exit(0);
    }
}

//load the data from the file to the array
// parameters: 
void loadData(ifstream &inFile, Task tasks[], int &listSize)
{
    while (!inFile.eof())
    {
        inFile.get(tasks[listSize].courseName, MAXCHAR, ';');
        inFile.ignore(200, ';');
        inFile.get(tasks[listSize].taskDescrip, MAXCHAR, ';');
        inFile.ignore(200, ';');
        inFile.get(tasks[listSize].dueDate, MAXCHAR, ';');
        inFile.ignore(200, '\n');
        listSize++;
    }
    inFile.close();
}

void displayMenu()
{
    cout << "Welcome to TaskTracker v.1" << endl;
    cout << "(a) Add a task" << endl;
    cout << "(l) List all tasks" << endl;
    cout << "(f) Find any tasks by course" << endl;
    cout << "(q) Quit" << endl << endl;
}

char readOption()
{
    char option;
    cout << "Please make a selection: ";
    cin.get(option);
    cin.ignore(100, '\n');
    return option;
}

void exeCommand(char option, Task tasks[], int &listSize)
{
    Task tempTask;// created object tempTask
    switch (tolower(option))
    {
    case 'a':
        cout << "You chose to add a task!" << endl;
        getUserTask(tempTask);//used aVideo as a parameter for getVideo
        addUserTask(tasks, listSize, tempTask);//tempTask 
        cout << endl << endl;
        break;
    case 'l':
        cout << "You chose print tasks!" << endl;
        printTasks(tasks, listSize);
        cout << endl << endl;
        break;
    case 'f':
        cout << "You chose to find an item by course!"<< endl;

        cout << endl << endl;
        break;
    case 'q':
        return;
    default:
        cout << "Invalid input!" << endl;
    }
}

void getUserTask(Task &tempTask)
{
    cout << "Please enter the course name {less than 101 characters): ";
    cin.get(tempTask.courseName, MAXCHAR);//user enters the course name
    cin.ignore(100, '\n');//ignores the next 100 characters or until newline

    cout << "Please enter a brief description of your task (less than 101 characters): ";
    cin.get(tempTask.taskDescrip, MAXCHAR);//user enters the task description
    cin.ignore(100, '\n');//ignores the next 100 characters or until newline

    cout << "Please enter the due date of this task. (mm/dd/yyy): ";
    cin.get(tempTask.dueDate, MAXCHAR);//user enters the task description
    cin.ignore(100, '\n');

}

void addUserTask(Task tasks[], int &listSize, Task tempTask)
{
    tasks[listSize++] = tempTask;
}

//prints the task list
void printTasks(Task tasks[], const int listSize)
{
    for (int i = 0; i < listSize; i++)
    {
        cout << tasks[i].courseName << ';' << tasks[i].taskDescrip << ';' << tasks[i].dueDate << endl;
    }
}

//writes to file at the end of the program
void writeFile(ofstream &outFile, Task tasks[], const int listSize)
{
    outFile.open("tasks.txt");
    for (int i = 0; i < listSize; i++)
    {
        outFile << tasks[i].courseName << ';' << tasks[i].taskDescrip << ';' << tasks[i].dueDate << endl;
    }
    return;
}

以下是调试器中的输出：

Welcome to TaskTracker v.1
(a) Add a task
(l) List all tasks
(f) Find any tasks by course
(q) Quit

Please make a selection: l
You chose print tasks!
CS162;Finish Project 2;04/10/2015
CS162
CS162;Finish Project4;05/10/2015
CS162

Welcome to TaskTracker v.1
(a) Add a task
(l) List all tasks
(f) Find any tasks by course
(q) Quit

我已经研究了好几个小时的代码并在网上搜索类似的案例，但似乎我的 fstream 能够读取并加载每一行的课程名称，但跳过了其他所有的任务描述和截止日期任务。有人可以指出我正确的方向吗？

菜单的 Add 选项似乎可以将新的用户输入任务加载到缓冲区中，但应该将缓冲区中的所有任务保存到输出文件的 writefile 函数似乎也不起作用。

我会继续寻找解决方案，但非常感谢任何帮助！

Answer 1

您的输入处理已损坏。我建议更多类似的内容：

void loadData(ifstream &inFile, Task tasks[], int &listSize)
{
    while (inFile.get(tasks[listSize].courseName, MAXCHAR, ';') &&
        inFile.ignore(200, ';') &&
        inFile.get(tasks[listSize].taskDescrip, MAXCHAR, ';') &&
        inFile.ignore(200, ';') &&
        inFile.get(tasks[listSize].dueDate, MAXCHAR, '\n'))
    {
        inFile.ignore(200, '\n');
        listSize++;
    }
    inFile.close();
}

产生以下输出：

Welcome to TaskTracker v.1
(a) Add a task
(l) List all tasks
(f) Find any tasks by course
(q) Quit

Please make a selection: l
You chose print tasks!
CS162;Finish Project 2;04/10/2015
CS162;Finish Project 3;04/20/2015
CS162;Finish Project 4;05/10/2015
CS162;Finish Project 5;05/20/2015

简而言之，您对第三个字段的请求也以 ';' 结尾（它在您的示例行中不执行此操作）正在跳到下一行，直到找到请求的分隔符，因此包括中间换行符和下一行的第一个字段以供骑行。当前行的其余部分已被后续ignore 丢弃。

祝你好运。