c - 菜单式程序

Question

我有一个任务是用 C 语言编写一个支持艺术画廊的程序。它必须是使用列表的基于菜单的程序。我编写了菜单的第一个功能，我需要一些帮助来编写其他三个功能。所以我有一个绘画的唯一代码的结构，作者姓名，绘画名称，价格，绘画年份。我必须创建一个函数，使用唯一的代码删除一幅画，打印出每幅画的所有信息，并使用所述代码再次修改一幅画。数据必须采用链表的动态类型结构。这是到目前为止的计划。

#include <stdio.h>

void addPainting(void);
void erasePainting(void);
void printData(void);
void modifyData(void);

int main()
{

    struct paintings
    {
        char code[20];
        char name[50];
        char paintingName[50];
        double price;
        int year;

    }painting[100];
    int choice;
    do
    {
        printf("Menu\n");
        printf("To add a painting press 1.\n");
        printf("To erase a painting press 2.\n");
        printf("To print data for all paintings by authors alphabetically press 3.\n");
        printf ("To modify data for a painting press 4.\n");
        printf("To exit the program press 5.\n");
        scanf("%d",&choice);

        switch(choice)
        {
           case 1:
            {
                addPainting();
                break;
            }
            case 2:
            {
                erasePainting();
                break;
            }
            case 3:
            {
                printData();
                break;
            }
            case 4:
            {
                modifyData();
                break;
            }

            default: printf ("Wrong choice. Try again\n");
                break;
        }
    }while (choice !=5);



void addPainting()
{
    FILE *fp;


    struct paintings painting;
    printf("Enter code:");
    scanf("%s", &painting.code);
    printf("Enter the name of the author:");
    scanf("%s", &painting.name);
    printf("Enter the name of the painting:");
    scanf("%s", &painting.paintingName);
    printf("Enter price:");
    scanf("%lf", &painting.price);
    printf("Enter the year of creation:");
    scanf("%d", &painting.year);
      if ((fp=fopen("paintings","wb"))==NULL)
        exit(1);
    if ((fwrite (&painting,sizeof(painting),1,fp)!=1))
        exit(2);
    fclose(fp);

}



}

Answer 1

第一个问题:您缺少 main() 函数的右大括号 ( } )。 (但我相信你知道)

结构大小错误的原因是您尝试在 void addPainting 中创建 struct Painting 的实例() 函数，当它在主函数中使用本地范围创建时，因此它对函数不可见。如果您想以这种方式使用它，请创建具有全局范围的结构绘画:

这将构建(并运行)，但仅限于定义的函数，其他函数将被注释掉。您还必须解决或询问其他问题。

已编辑修复 scanf() 语句，显示 fopen()/fclose() 的使用，使用 sprintf()/fputs() 创建和写入字符串.. .

void addPainting(void);
//void erasePainting(void);
//void printData(void);
//void modifyData(void);

typedef    struct //created with global scope, visible to all functions
{
    char code[20];
    char name[50];
    char paintingName[50];
    double price;
    int year;

}PAINTING;

PAINTING painting[100];//array of instance of PAINTING

#define PATH "C:\\play\\painting.txt"  //edit to your need


int main()
{

    int choice;
    do
    {
        printf("Menu\n");
        printf("To add a painting press 1.\n");
        printf("To erase a painting press 2.\n");
        printf("To print data for all paintings by authors alphabetically press 3.\n");
        printf ("To modify data for a painting press 4.\n");
        printf("To exit the program press 5.\n");
        scanf("%d",&choice);

        switch(choice)
        {
           case 1:
            {
                addPainting();
                break;
            }
            case 2:
            {
                //erasePainting();
                break;
            }
            case 3:
            {
                //printData();
                break;
            }
            case 4:
            {
                //modifyData();
                break;
            }

            default: printf ("Wrong choice. Try again\n");
                break;
        }
    }while (choice !=5);
}

void addPainting(void)
{
    FILE *fp;
    char stringToWrite[80];
    //Note: this function could be prototyped with an int argument
    //        to be used as an index for the array arguments of your
    //        structure.  Currently, the indexes are hard-coded to 0, 


    printf("Enter code:");
    //scanf("%s", &painting[0].code); 
    scanf("%s", painting[0].code); //& not needed for char array (char *) et. al.
    printf("Enter the name of the author:");
    scanf("%s", painting[0].name);
    printf("Enter the name of the painting:");
    scanf("%s", painting[0].paintingName);
    printf("Enter price:");
    scanf("%lf", &painting[0].price);
    printf("Enter the year of creation:");
    scanf("%d", &painting[0].year);
    fp = fopen (PATH, "a");//open for create/append text file (not write binary, "wb")

    if(fp)
    {
        sprintf(stringToWrite, "Painting Code is: %s\n", painting[0].code);
        fputs(stringToWrite, fp);
        // do others same way...
        //...
        fclose(fp);
    }
}