感谢您的预期帮助。我一直在看这段代码几个小时和几天，但我似乎无法找出为什么我的 delRecFunc() 一次不只删除一条记录。它似乎正在删除整个文件。
#include <iostream>
#include <fstream>
#include <stdlib.h>
#include <string>
#include <iomanip>
using namespace std;
const int NAME_SIZE = 40, ADDR_SIZE = 50, PHONE_SIZE = 14;
char y, Y;
struct Info
{
char name[NAME_SIZE];
int age;
char address1[ADDR_SIZE];
char phone[PHONE_SIZE];
}people;
void popFunc();
void dispFunc();
void appFunc();
void delRecFunc();
void searchFunc();
void modRecFunc();
int getNumRec();
int validateRecord (int);
void wipeFunc();
int main()
{
Info person;
char choice, option;
cout << " The file we are working with is named stuff.dat,\n"
<< "I will let you know if it unavailable " << endl;
cout << " "<< endl;
do
{
cout << " \n \n Simple People Records... \n \n \n "
<< " Please choose from the following options: \n \n \n"
<< " 1. POPULATE THE BINARY FILE \n"
<< " 2. DISPLAY THE CONTENTS OF THE FILE\n"
<< " 3. APPEND A RECORD TO THE FILE\n"
<< " 4. DELETE A RECORD FROM THE FILE\n"
<< " 5. SEARCH FOR A CERTAIN RECORD\n"
<< " 6. MODIFY A CERTAIN RECORD. \n"
<< " 7. WIPE OUT THE ENTIRE CONTENTS OF THE FILE. \n" <<endl;
cin >> option;
switch(option)
{
case '1': popFunc();
system("pause");
break;
case '2': dispFunc();
break;
case '3': appFunc();
break;
case '4': delRecFunc();
break;
case '5':searchFunc();
break;
case '6':modRecFunc();
break;
case '7':wipeFunc();
break;
}
}
while(choice!= 1000);
system("pause");
return(0);
}
void popFunc()
{ fstream file("stuff.dat", ios::out | ios::binary);
if (file.fail())
{
cout << "the file does not exist so we are creating it now... ";
system("pause");
file.open("stuff.dat", ios::out);
}
cout << "enter the following data about a person: "<<endl;
cout << "Name: " <<endl;
cin >> ws;
cin.getline(people.name,NAME_SIZE);
cout << "Age (integers only or the program will be corrupted): " <<endl;
cin >> people.age;
cin.ignore(); //skip over the remaining newline.
cout<< "Address line 1: ";
cin >> ws;
cin.getline(people.address1,ADDR_SIZE);
cout << "Phone: in the following format ie: 201.123.1234 (no hyphens)";
cin >> ws;
cin.getline(people.phone,PHONE_SIZE);
file.write(reinterpret_cast<char *>(&people), sizeof(people));
file.close();
}
void dispFunc()
{
ifstream file;
file.open("stuff.dat", ios::binary);
if (file.fail())
{
cout << "the file does not exist so we are creating it now... ";
system("pause");
file.open("stuff.dat", ios::out);
}
while(file.read(reinterpret_cast<char *> (&people), sizeof(people)))
{
cout << "Name: "<< people.name <<endl;
cout << "Age: "<< people.age <<endl;
cout << "Address: " <<people.address1 <<endl;
cout << "Phone #: " <<people.phone << " \n\n"<<endl;
}
file.close();
}
void appFunc()
{ ofstream file;
file.open("stuff.dat", ios::binary | ios::app);
if (file.fail())
{
cout << "the file does not exist so we are creating it now... ";
system("pause");
file.open("stuff.dat", ios::out);
}
cout << "Name: " <<endl;
cin >> ws;
cin.getline(people.name,NAME_SIZE);
cout << "Age (integers only or the program will be corrupted): " <<endl;
cin >> people.age;
cin.ignore(); //skip over the remaining newline.
cout<< "Address line 1: ";
cin >> ws;
cin.getline(people.address1,ADDR_SIZE);
cout << "Phone: Phone: in the following format ie: 201.123.1234 (no hyphens)";
cin >> ws;
cin.getline(people.phone,PHONE_SIZE);
file.write(reinterpret_cast<char *>(&people), sizeof(people));
file.close();
}
void searchFunc()
{
int count =1;
int answer;
long recNum;
int recCount = getNumRec();
fstream search;
search.open("stuff.dat", ios::in | ios:: binary);
cout << " Please enter 1 - " <<recCount ;
cout << " and I will display the data /n"<<endl;
cin >>recNum;
while(recNum<1 || recNum > recCount)
{
cout<<"Please enter a number between 1 and "<<recCount<<": ";
cin>>recNum;
}
answer = validateRecord(recNum);
}
void modRecFunc()
{
int count=1;
int answer;//to hold choice from the user
long recNum;//to hold a record number
int recCount = getNumRec();//variable to hold how many record the file has
fstream search;
//open file
search.open("stuff.dat",ios::in|ios::out|ios::binary);
cout<<"Which record do you wish to edit? ";
cin>>recNum;//variable to store the record the user wish to delete
//validation so the user is not allow to enter more numbers than the actual
//size of the file
while(recNum<1||recNum>recCount)
{
cout<<"Please enter a number between 1 and "<<recCount<<": ";
cin>>recNum;
}
//move pointer to desire position
cout<<endl;
answer= validateRecord(recNum);//make sure the record is the right one
cout<<endl;
if(answer==1)
{
//get the new data
cout << "Name: " <<endl;
cin >> ws;
cin.getline(people.name,NAME_SIZE);
cout << "Age (integers only or the program will be corrupted): " <<endl;
cin >> people.age;
cin.ignore(); //skip over the remaining newline.
cout<< "Address line 1: ";
cin >> ws;
cin.getline(people.address1,ADDR_SIZE);
cout << "Phone: Phone: in the following format ie: 201.123.1234 (no hyphens)";
cin >> ws;
cin.getline(people.phone,PHONE_SIZE);
search.seekp((recNum-1)*sizeof(people), ios::beg);
search.write(reinterpret_cast<char *>(&people), sizeof(people));
}
cout<<endl;
search.close();
}
void wipeFunc()
{ char option;
ofstream file;
cout << "This option will delete all the contents of the file "<<endl;
cout << " Are you sure you want to delete the file? Y or N " <<endl;
cin >> option;
if (option == 'y' || option == 'Y')
{
cout << " Warning, if you hit Y, you will lose everything " <<endl;
cout << " Y to confirm, N to return to main menu" <<endl;
cin >> option;
if(option == 'y' || option == 'Y')
{
file.open("stuff.dat", ios::out | ios::binary);
file.close();
}
}
}
int validateRecord (int recNum)
{
int answer;// variable to hold the answer from the user
fstream validate;
//open file
validate.open("stuff.dat",ios::in|ios::out|ios::binary);
validate.seekg((recNum-1)*sizeof(people));
//read record from file
validate.read(reinterpret_cast<char*>(&people),sizeof(people));
cout<<endl;
cout << "the name is "<< people.name <<endl;
cout << "the age is "<< people.age <<endl;
cout << "the address is" <<people.address1 <<endl;
cout << "the phone is Phone: " <<people.phone <<endl;
cout<<"Is this the file you want?\n"
"1. yes\n"
"2. no\n"
"Choice: ";
cin>>answer;
// validate answer to 1 or 2
while(answer<1||answer>2)
{
cout<<"enter only 1 or 2: ";
cin>>answer;
}
cout<<endl;
validate.close();
return answer;
}
int getNumRec()
{
int count =0;
fstream file;
file.open("stuff.dat", ios::in|ios::binary);
if (file.fail())
{
cout << "Error opening file. Program aborting.\n";
}
file.read(reinterpret_cast<char *>(&people),sizeof(people));
while (!file.eof())
{
count++;
file.read(reinterpret_cast<char *>(&people),
sizeof(people));
}
file.close();//close the file
return count;//return count the erase function
}
void delRecFunc()
{
int count=1;
int answer; //to hold choice from the user
double recNum;//to hold the record number the user wishes to delete
int recCount = getNumRec();//variable to hold how many record the file has
fstream erase;
erase.open("stuff.dat", ios::in|ios::out|ios::binary);
Info Temp; //*****NEW TEMP STRUCT VAR*****//
cout << "Please enter the phone number of the person you want to delete in this
format 201.123.1111)";
cin >> recNum;
//move pointer to desire position
erase.seekg((recNum-1)*sizeof(people));
//read record from file
erase.read(reinterpret_cast<char*>(&people),sizeof(people)); //read record from file
//get answer from the validateRecord function
answer = validateRecord (recNum);
if(answer == 1)
{
ofstream copy;
copy.open("stuff2.dat", ios::out | ios::binary);
erase.seekg(0*sizeof(people)); // Move pointer to beginning of the file
erase.read(reinterpret_cast<char*>(&people),sizeof(people));
// BEGIN NEW CODE //
// Keep looping till there are no more records in the customer.dat file
while (!erase.eof())
{
// If the id that the user wants deleted doesnt match the current
// records id, copy it to the temp directory
if(people.phone != Temp.phone)
{
// Write the record to copy.dat
copy.write(reinterpret_cast<char*>(&people),sizeof(Info));
}
// Read the next line from customer.dat
erase.read(reinterpret_cast<char*>(&people),sizeof(Info));
}
// Close both files
erase.close();
copy.close();
}
// Delete the Old customer.dat file
remove("stuff.dat");
// Rename the temporary holder to "customer.dat"
rename("stuff2.dat","stuff.dat");
}