大家好,在上一個(gè)問(wèn)題中,我能夠獲取要加載到文件中的結(jié)構(gòu)數(shù)據(jù),但現(xiàn)在問(wèn)題是我在檢索它時(shí)會(huì)得到垃圾值.
文件內(nèi)容：settings.bin
110#NormalCompression Level210#NormalCompression Level310#NormalCompression Level410#NormalCompression Level510#NormalCompression Level碼
#include<cstdlib>#include<iostream>#include<string>#include<iomanip>#include<fstream.h>using namespace std;const char* ErrorLogFilePath = "resources\\error.txt";const char* SettingsFilePath = "resources\\settings.bin";const int NoOfSettings = 5;struct Setting { int SettingID; int SettingINTValue; double SettingDOUBLEValue; char SettingCHARValue; string SettingSTRINGValue; string SettingName;};istream& operator>>(istream& _is, Setting& _s) { _is>>_s.SettingID; _is>>_s.SettingINTValue; _is>>_s.SettingDOUBLEValue; _is>>_s.SettingCHARValue; _is>>_s.SettingSTRINGValue; _is>>_s.SettingName;}ostream& operator<<(ostream& _os, const Setting& _s) { _os<<_s.SettingID; _os<<_s.SettingINTValue; _os<<_s.SettingDOUBLEValue; _os<<_s.SettingCHARValue; _os<<_s.SettingSTRINGValue; _os<<_s.SettingName;}class ErrorReport {public: fstream ErrorFile; void PostError(string Title,string Data,int ErrorID) { ErrorFile.open(ErrorLogFilePath,ios::out); ErrorFile.close(); }} Error;class SettingsClass {public: Setting setting[NoOfSettings]; void ResetSettings() { fstream SettingFile; Setting defaultsetting[NoOfSettings]; for(int i=1; i<=NoOfSettings; i ) { defaultsetting[i-1].SettingID = i; defaultsetting[i-1].SettingINTValue = 0; defaultsetting[i-1].SettingDOUBLEValue = 0; defaultsetting[i-1].SettingCHARValue = '#'; defaultsetting[i-1].SettingSTRINGValue = "null"; switch(i) { default: defaultsetting[i-1].SettingName = "Compression Level"; defaultsetting[i-1].SettingSTRINGValue = "Normal"; defaultsetting[i-1].SettingINTValue = 1; break; } } SettingFile.open(SettingsFilePath,ios::binary|ios::out); if(SettingFile.is_open()) { for(size_t i=0; i<NoOfSettings; i) { SettingFile<<defaultsetting[i]; } } else { cout<<"Error!"; } SettingFile.close(); } void _SettingsClass() { fstream SettingFile; SettingFile.open(SettingsFilePath,ios::binary|ios::in); Setting TempSettings[NoOfSettings]; if(SettingFile.is_open()) { for(size_t i=0; i<NoOfSettings; i) { SettingFile>>TempSettings[i]; } } else { cout<<"Error..."; } SettingFile.close(); for(int i=0; i<NoOfSettings; i ) { cout<<TempSettings[i].SettingINTValue<<"\n"; } }} Settings;int main(int argc, char *argv[]){ Settings._SettingsClass();// cout<<Settings.GetSetting(1).SettingName; system("PAUSE"); return EXIT_SUCCESS;}產(chǎn)量
44730761302686384現(xiàn)在為什么我得到那些垃圾值？任何人都可以幫助我,因?yàn)槲艺J(rèn)為它不應(yīng)該像這樣(？).我應(yīng)該為該struct數(shù)組的每個(gè)元素得到1.
提前致謝！
解決方法:
格式化輸入需要分隔符,因此它知道何時(shí)停止讀取特定值.即使您以二進(jìn)制模式打開(kāi)文件,您所編寫(xiě)的內(nèi)容本質(zhì)上也是一個(gè)沒(méi)有分隔符的文本文件,因此您無(wú)法將其讀回.
如果你必須有一個(gè)二進(jìn)制文件,那么這是使用你的結(jié)構(gòu)讀/寫(xiě)一個(gè)的方法：
#include <iostream>#include <string>#include <iomanip>#include <fstream>#include <vector>const char* SettingsFilePath = "settings.bin";struct Setting{ int SettingID; int SettingINTValue; double SettingDOUBLEValue; char SettingCHARValue; std::string SettingSTRINGValue; std::string SettingName; Setting() : SettingID(0) , SettingINTValue(0) , SettingDOUBLEValue(0) , SettingCHARValue(0) { } void Write(std::fstream& out) { out.write(reinterpret_cast<const char*>(&SettingID), sizeof(SettingID)); out.write(reinterpret_cast<const char*>(&SettingINTValue), sizeof(SettingINTValue)); out.write(reinterpret_cast<const char*>(&SettingDOUBLEValue), sizeof(SettingDOUBLEValue)); out.write(reinterpret_cast<const char*>(&SettingCHARValue), sizeof(SettingCHARValue)); size_t str_size = SettingSTRINGValue.size(); out.write(reinterpret_cast<const char*>(&str_size), sizeof(str_size)); out.write(SettingSTRINGValue.c_str(), SettingSTRINGValue.size()); str_size = SettingName.size(); out.write(reinterpret_cast<const char*>(&str_size), sizeof(str_size)); out.write(SettingName.c_str(), SettingName.size()); } void Read(std::fstream& in) { in.read(reinterpret_cast<char*>(&SettingID), sizeof(SettingID)); in.read(reinterpret_cast<char*>(&SettingINTValue), sizeof(SettingINTValue)); in.read(reinterpret_cast<char*>(&SettingDOUBLEValue), sizeof(SettingDOUBLEValue)); in.read(reinterpret_cast<char*>(&SettingCHARValue), sizeof(SettingCHARValue)); size_t str_size; std::vector<char> str_data; in.read(reinterpret_cast<char*>(&str_size), sizeof(str_size)); str_data.resize(str_size); in.read(&str_data[0], str_size); SettingSTRINGValue.assign(str_data.begin(), str_data.end()); in.read(reinterpret_cast<char*>(&str_size), sizeof(str_size)); str_data.resize(str_size); in.read(&str_data[0], str_size); SettingName.assign(str_data.begin(), str_data.end()); } void Print(const std::string& title) { std::cout << title << "\n"; std::cout << std::string(title.size(), '-') << "\n"; const size_t w = 22; std::cout << std::setw(w) << std::right << "SettingID : " << SettingID << "\n"; std::cout << std::setw(w) << std::right << "SettingINTValue : " << SettingINTValue << "\n"; std::cout << std::setw(w) << std::right << "SettingDOUBLEValue : " << SettingDOUBLEValue << "\n"; std::cout << std::setw(w) << std::right << "SettingCHARValue : " << SettingCHARValue << "\n"; std::cout << std::setw(w) << std::right << "SettingSTRINGValue : " << SettingSTRINGValue << "\n"; std::cout << std::setw(w) << std::right << "SettingName : " << SettingName << "\n"; std::cout << "\n"; }};int main(){ { Setting s; s.Print("Default before Write"); s.SettingID = 1; s.SettingINTValue = 2; s.SettingDOUBLEValue = 3.5; s.SettingCHARValue = 'Z'; s.SettingSTRINGValue = "Blah Blah"; s.SettingName = "Some Settings"; std::fstream f(SettingsFilePath, std::ios::out | std::ios::binary); s.Write(f); s.Print("Values written to file"); } { Setting s; s.Print("Default before read"); std::fstream f(SettingsFilePath, std::ios::in | std::ios::binary); s.Read(f); s.Print("Values after read"); } return EXIT_SUCCESS;}聯(lián)系客服
