C++將矢量保存/加載到文件中

Question

我正在用C++創建日曆應用程序。

這裏是我的代碼：

class appointment 
{ 
public: 
    appointment(string aDate, string aTime, string aType, 
    string aLocation, string aComments, bool aIsImportant, 
    string aReminderDate, string aReminderTime) 
    { 
     appDate = aDate; 
     appTime = aTime; 
     appType = aType; 
     appLocation = aLocation; 
     appComments = aComments; 
     appIsImportant = aIsImportant; 
     appReminderDate = aReminderDate; 
     appReminderTime = aReminderTime; 
    } 
    void setDate(string aDate) 
    { 
     appDate = aDate; 
    } 
    void setTime(string aTime) 
    { 
     appTime = aTime; 
    } 
    void setType(string aType) 
    { 
     appType = aType; 
    } 
    void setLocation(string aLocation) 
    { 
     appLocation = aLocation; 
      } 
    void setComments(string aComments) 
    { 
     appComments = aComments; 
    } 
    void setIsImportant(bool aIsImportant) 
    { 
     appIsImportant = aIsImportant; 
    } 
    void setReminderDate(string aReminderDate) 
    { 
     appReminderDate = aReminderDate; 
    } 
    void setReminderTime(string aReminderTime) 
    { 
     appReminderTime = aReminderTime; 
    } 
    string getDate() 
    { 
     return appDate; 
    } 
    string getTime() 
    { 
     return appTime; 
    } 
    string getType() 
    { 
     return appType; 
    } 
    string getLocation() 
    { 
     return appLocation; 
    } 
    string getComments() 
    { 
     return appComments; 
    } 
    bool getIsImportant() 
    { 
     return appIsImportant; 
    } 
    string getReminderDate() 
    { 
     return appReminderDate; 
    } 
    string getReminderTime() 
    { 
     return appReminderTime; 
    } 
private: 
    appointment(); 
    string appDate; 
    string appTime; 
    string appType; 
    string appLocation; 
    string appComments; 
    bool appIsImportant; 
    string appReminderDate; 
    string appReminderTime; 
    //person owner; 
}; 

class calendar 
{ 
public: 
    calendar() 
    { 
     loadFromFile(); 
    } 
    ~calendar() 
    { 
     saveToFile(); 
    } 
    void createAppointment(string aDate, string aTime, string aType, 
    string aLocation, string aComments, bool aIsImportant, 
    string aReminderDate, string aReminderTime) 
    { 
     appointment newAppointment(string aDate, string aTime, string aType, 
     string aLocation, string aComments, bool aIsImportant, 
     string aReminderDate, string aReminderTime); 
     //appointments.resize(appointments.size() + 1,newAppointment); 
    } 
private: 
    vector<appointment> appointments; 
    string calCurrentDate; 
    string calCurrentTime; 
    void loadFromFile() 
    { 
     //Code to load appointments from file 
    } 
    void saveToFile() 
    { 
     //Code to save appointments to file 
    } 
}; 

我可以請有一些幫助，下面：

當調用構造函數，我想加載任命的文件（loadFromFile（）方法）對象並設置'約會'變量以具有此文件的內容。在saveToFile（）方法之後，我想將約會向量的內容保存到文件中。

此外，調用createAppointment（）方法時，我想將矢量的大小增加1，並將內容添加到矢量中。我不確定正確的代碼。

更新保存/從文件中

void loadFromFile() 
    { 
     ifstream iStream("file.ext", ios::binary); 
     fileHeader_t fHeader; 
     iStream.read((char*)&fHeader, sizeof(fileHeader_t)); 
     if (fHeader.magicNumber = 0xDEADBEAF) 
     { 
      appointments.resize(fHeader.appointmentCount); iStream.read((char*)&appointments[0], fHeader.appointmentCount * sizeof(appointment)); 
     } 
    } 
    void saveToFile() 
    { 
     ofstream oStream("file.ext", ios::binary); 
     fileHeader_t fHeader; 
     fHeader.magicNumber = 0xDEADBEAF; 
     fHeader.appointmentCount = appointments.size(); 
     oStream.write((char*)&fHeader, sizeof(fileHeader_t)); 
     oStream.write((char*)&appointments[0], sizeof(appointment) * appointments.size()); 
    } 

Answer 1

加載你將不得不拿出自己的文件格式（即手動保存一行每個記錄），或使用類似Boost::serialization。

Answer 2

載體是所謂連續的，所以你不應該對使用ifstream的裝載他們的任何問題，如果我是你，我會創建一個基本報頭爲你的二進制文件的東西，如：

struct fileHeader_s 
{ 
    DWORD magicNumber; 
    size_t appointmentsCount; 
}fileHeader_t; 

然後，在循環中，只需讀取預約值中的每個項目，並使用appointmentments.push_back（item）; 你應該在createAppointment中做同樣的事情，不要調整vector的大小，只要push_back（newAppointment）;