从.txt [c++]读取代码

我正试图编写一款冒险游戏，从文本文件上的脚本读取。该程序编译和运行，但它没有从我的。txt文件中读取，我无法弄清楚出了什么问题。

在GetAreaInfo函数中

"fin.seekg(NULL,ios::beg);"显示一个警告:

"main.cpp:92:28: warning:给std::basic_istream<_CharT， _Traits>&amp的非指针参数1传递NULL;std::basic_istream<_CharT， _Traits>::seekg(std::basic_istream<_CharT， _Traits>::off_type, std::ios_base::seekdir) [with _CharT = char;_Traits = std::char_traits;std:: basic_istream_chart， _Traits>::off_type = long int;std::ios_base::seekdir = std::_Ios_Seekdir]' [-Wconversion-null]"

我不知道如何解决这个问题，但我相信这就是问题所在。如有任何帮助，不胜感激

//file libraries
#include <iostream>
#include <fstream>
#include <string>
#include <windows.h>
using namespace std;
#define GAMEFILE "world.txt"//read in for the world data
#define CONTINUE    1
#define QUIT            0
//user libraries
struct tArea{//structure that holds the info for the main area
    string strCurrentArea;//name of current area
    string strDescription;//description of current area
    string strNorth;//name of area to the north
    string strSouth;//name of area to the south
    string strEast;//name of area to the east
    string strWest;//name of area to the west
};
//global constants
//function prototypes
void DisplayArea(tArea &area);
void GetAreaInfo(ifstream&,tArea &area);
void Move(ifstream&,tArea &area,string);
int Input(ifstream&,tArea &area);
//execution
int main(){
    ifstream fin;//pointer that opens and reads from file
    tArea area;//area structure data
    fin.open(GAMEFILE);//
    if(fin.fail()){
        cout<<"UNABLE TO FIND GAME FILEn";
        return -1;
    }
    fin>>area.strCurrentArea>>area.strCurrentArea;//reads in the start point for the game
    GetAreaInfo(fin,area);//calls function to receive info from the file
    DisplayArea(area);//calls function to display the area to the user
    while(1){//main game loop

        if(Input(fin,area)==QUIT){//if user enters quit, game ends
            break;
        }
    }
    fin.close();//closes file
    Sleep(1000);//1 second delay before ending
    return 0;
}
/**********************************************************/
//*****************DisplayArea*****************************/
//******Function is called to display area description*****/
/**********************************************************/
void DisplayArea(tArea &area)
{
    cout<<area.strDescription<<endl<<endl;      
}
/**********************************************************/
//*****************GetAreaInfo*****************************/
//******Function is called to read in the area*************/
//************information from the file********************/
/**********************************************************/
void GetAreaInfo(ifstream &fin,tArea &area){
    string strTemp="";
    string strTemp2="";//temporary for reading in info
    string strArea="<"+area.strCurrentArea+">";//looks for the room name in brackets to find easier i.e instead of main it reads in <main>
    fin.seekg(NULL,ios::beg);//starts the header search from the beginning of the file
    fin.clear();//allows the file to be read through multiple times
    while(getline(fin, strTemp, 'n')){//while loop reads file til it finds the correct area heading
        if(strTemp==strArea){
            getline(fin, area.strDescription, '*');//if it finds the correct area heading, it reads its info    
            // Read past the direction blocks (I.E. <north>) and store the room name for that direction
            fin>>strTemp>>area.strNorth;                
            fin>>strTemp>>area.strEast;             
            fin>>strTemp>>area.strSouth;                
            fin>>strTemp>>area.strWest;//it then read in the surrounding area titles by skipping their <area> descriptors               

            return;                                 
        }
    }
}
/**********************************************************/
//*********************Move********************************/
//******Function is called to move through the*************/
//****game if there is an area in that direction***********/
/**********************************************************/
void Move(ifstream &fin,tArea &area, string strArea){
    if(strArea=="None"){//detects if there is no area in the direction inputted             
        cout<<"You are unable to travel that wayn";//displays error message and returns the function
        return;                                 
    }
    else{
        area.strCurrentArea=strArea;// Sets the current area to the new one
    GetAreaInfo(fin, area); // Passes in the file pointer so the new area data is read  
    DisplayArea(area);// Displays current area
    }
}
/**********************************************************/
//*********************Input*******************************/
//******Main game mechanic feature. Receives **************/
//****user input and reacts to it accordingly to **********/
//*******progress through the game*************************/
/**********************************************************/
int Input(ifstream &fin, tArea &area){
    string strInput="";//holds user input
    cout<<endl<<":";//displays prompt
    cin>>strInput;//reads in the user input
    if(strInput=="look"){
        DisplayArea(area);//calls function to give current area description
    }
    else if(strInput=="north"){
        Move(fin,area,area.strNorth);//calls function to move north if possible
    }
    else if(strInput=="east"){
        Move(fin,area,area.strEast);//calls function to move east if possible
    }
    else if(strInput=="west"){
        Move(fin,area,area.strWest);//calls function to move west is possible
    }
    else if(strInput=="south"){//calls function to move south if possible
        Move(fin,area,area.strSouth);
    }
    else if(strInput=="help"||strInput=="?"){//displays commands to user
        cout<<"Commands: north east west south look quit helpn";
    }
    else if(strInput=="quit"){//ends game
        cout<<"Quit game?n";
        return QUIT;
    }
    else{//displays when invalid input is received
        cout<<"Invalid inputn";
    }
    return CONTINUE;
}