无法在 C 程序中正确显示文件中的数据

Question

我现在遇到了一个小问题，即 C 程序无法在屏幕上正确打印结果。甚至程序也可以写入用户的输入并将其打印到记事本中。使用的文件类型是随机访问文件，我需要将数据写入名为 toyota.txt 的二进制文件任何人都可以教我那里有什么问题？非常感谢！

/*program 1: write the data into file toyota.txt*/

#include<stdio.h>

struct vehicledata{
    char vnum[100];
    int cnum;
    float f50[100];
    float f100[100];
    float f200[100];
    float f400[100];
    float f800[100];
};

int main()
{
    FILE *fptr;
    struct vehicledata toyota;
    if((fptr = fopen("toyota.txt","wb")) == NULL)
    {
        printf("Error! File fail opened!");
    }
    else
    {
        printf("This program can create a text file named toyota.txt \n");
        printf("and save the value of car noise level(dB) with\n different frequency and vehicle numbers into file\n\n");
        printf("Enter car number(1 to 10, enter 0 to end input)\n");
        printf("? ");
        scanf("%d", &toyota.cnum);

        while (toyota.cnum != 0)
        {
            printf("\nEnter Vehicle and car noise level(dB) at 50Hz, 100Hz, 200Hz, 400Hz and 800Hz\n");
            printf("? ");
            scanf("%s %f %f %f %f %f", toyota.vnum, &toyota.f50, &toyota.f100, &toyota.f200, &toyota.f400, &toyota.f800);
            fseek(fptr, (toyota.cnum - 1) * sizeof(struct vehicledata), SEEK_SET);
            fwrite(&toyota, sizeof(struct vehicledata), 1, fptr);
            printf("\nEnter car number (1 to 100, 0 to end input) \n");
            scanf("%d", &toyota.cnum);
        }
    }

    fclose(fptr);
    return 0;
}

/*program 2 : reads the data from the file toyota.txt and find
the car that emanates the minimum noise at 200Hz*/
#include <stdio.h>
#include <stdlib.h>

struct vehicledata{
    char vnum[100];
    int cnum;
    float f50[100];
    float f100[100];
    float f200[100];
    float f400[100];
    float f800[100];
};

int main()
{
    FILE *fptr;
    struct vehicledata toyota;
    if ((fptr = fopen("toyota.txt","rb")) == NULL)//open and read data in the file
    {
        printf("Error! File fail opened!");
    }
    else
    {
        printf("This program can read and display the data from the toyota.txt\n and find car that have minimum noise in 200Hz\n\n");
        printf("\nThe information in the toyota.txt are shown at below:\n");
        printf("\n\t\t\t\tCar Noise Level(dB)\t\t\t");
        printf("\n=======================================================================\n");
        printf("%s\t\t%s\t%s\t%s\t%s\t%s\t\n","Vehicle Number","50Hz","100Hz","200Hz","400Hz","800Hz");
        printf("=======================================================================\n");
        while(!feof(fptr))
        {
            fread(&toyota, sizeof(struct vehicledata), 1, fptr);
            if(toyota.cnum != 0)
            {
                printf("%s\t\t\t%.2f\t%.2f\t%.2f\t%.2f\t%.2f", toyota.vnum, toyota.f50, toyota.f100, toyota.f200, toyota.f400, toyota.f800);
            }
        }
    }
    fclose(fptr);
    return 0;
}

Answer 1

实现的主要问题是vehicledata结构错误。

尝试

struct vehicledata {
    char vnum[100];
    int cnum;
    float f50;
    float f100;
    float f200;
    float f400;
    float f800;
};

工作起来会容易很多。

您似乎不想为每辆车收集 500 (5 * 100) 个不同的频率数据。

无法在 C 程序中正确显示文件中的数据

Can't show the data from the file properly in C program

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