这段代码中为什么写入文件的数据全是乱码,第二次打开文件出错,程序直接退出了,是什么原因?
//randbin.c--用二进制I/O进行随机访问
#include<stdio.h>
#include<stdlib.h>
#define ARSIZE 1000

int main(void)
{
    double numbers[ARSIZE];
    double value;
    const char * file = "numbersdat";
    int i;
    long pos;
    FILE *iofile;

    //创建一组double类型的值
    for (i = 0; i < ARSIZE; i++)
    {
        numbers[i] = 100.0*i + 1.0 / (i + 1);
    }
    //尝试打开文件
    if ((iofile = fopen(file, "wb")) == NULL)
    {
        fprintf(stderr, "Could not open %s for output.\n", file);
        exit(EXIT_FAILURE);
    }
    //以二进制格式把数组写入文件
    fwrite(numbers, sizeof(double), ARSIZE, iofile);
    fclose(iofile);
    if ((iofile = fopen(file, "rb")) == NULL);
    {
        fprintf(stderr, "Could not open %s for random access.\n", file);
        exit(EXIT_FAILURE);
    }
    //从文件中读取选定的内容
    printf("Enter an index in the range 0-%d.\n", ARSIZE - 1);
    while (scanf("%d", &i) == 1 && i >= 0 && i < ARSIZE)
    {
        pos = (long)i * sizeof(double);  //计算偏移量
        fseek(iofile, pos, SEEK_SET);
        fread(&value, sizeof(double), 1, iofile);
        printf("The value there if %f.\n", value);
        printf("Next index (out of range to quit):\n");
    }
    //完成
    fclose(iofile);
    puts("Bye!");

    return 0;
}

[此贴子已经被作者于2018-11-26 16:12编辑过]

//if ((iofile = fopen(file, "rb")) == NULL);
if ((iofile = fopen(file, "rb")) == NULL)

    //从文件中读取选定的内容
    fread(numbers, sizeof(double), ARSIZE, iofile);
    fclose(iofile);
    printf("Enter an index in the range 0-%d.\n", ARSIZE - 1);
    while (scanf("%d", &i) == 1 && i >= 0 && i < ARSIZE)
    {
        printf("The value there if %f.\n", numbers[i]);
        printf("Next index (out of range to quit):\n");
    }

眼睛真好使,我检查了好几遍了,非常感谢,终于正常了