快速预订问题 [英] Quick booking issue

问题描述

#include <stdio.h>

#pragma pack(push)
#pragma (1)

typedef struct contact {    
    char firstname [40];    
    char lastname [40]; 
    char address [100]; 
    char phone[10];
}contact;

#pragma pack(pop)

int main ()
{   FILE *pFile;
    contact entry = {"", "", "", ""};
    char choice;

    pFile = fopen("C:\\contacts.txt", "w+");

if(!pFile){
    printf("File could not be open");
    return 1;
    }

printf("Choose a selection\n\n");
printf("1. Enter First Name\n");
printf("2. Enter Last Name\n");
printf("3. Enter Address\n");
printf("4. Enter Phone Number\n\n");
scanf( "%d", &choice);

switch (choice){

     case 1:
        printf("First name: \n");     
        fgets(entry.firstname, sizeof(entry.firstname),pFile);
        break;
     case 2:
        printf("Last name: \n");      
        fgets(entry.lastname, sizeof(entry.lastname),pFile);
        break;
     case 3:
        printf("Address: \n");    
        fgets(entry.address, sizeof(entry.address),pFile);
        break;
     case 4:
        printf("Phone Number: \n");   
        fgets(entry.phone, sizeof(entry.phone),pFile);
        break;
     default:
        printf(" No Choice selected, Ending Address Book Entry system");
        break;
    }
        fwrite(&entry, sizeof(contact), 1, pFile);

        printf("Enter a new contact?");
        scanf("%s", &choice);

     //while(choice != 'n');

fclose(pFile);

getchar();
return 0;
}

这段代码在我选择一个条目后，输入它崩溃说堆栈变量'条目'已损坏。我相信，这是我的fwrite函数，我使用。我知道第一个参数fwrite寻找是一个指向要写的元素数组的指针，但我想我现在只是困惑。

This code after I choose an entry and after I put an entry in and press enter it crashes saying Stack around the variable 'entry' was corrupted. I'm fairly confident that it is my fwrite function that I'm using. I know the first parameter fwrite looks for is a pointer to an array of elements to be written but I think I'm just confused right now. Any help would be much appreciated.

推荐答案

您应该更改所有

fgets(entry.firstname, sizeof(entry.firstname),pFile);

到

fgets(entry.firstname, sizeof(entry.firstname),stdin);

因为您正在从控制台阅读，而不是文件。

Because you're reading from the console, not the file.

此外，使用

scanf("%s", &choice);

和

scanf( "%d", &choice);

您尝试读取字符串和数字并将其存储在 char 。它们都应为

you're trying to read a string and a digit and store it in a char. They both should be

scanf("%c", &choice);

也就是说，你应该考虑使用 ifstream ， cin ， getline 和 std :: string 让您的生活更轻松，如果你不寻求最大的性能。

That said, you should think about rewriting this using ifstream, cin, getline, and std::string to make your life easier if you're not looking for maximum performance.

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