这是代码，它按平均跑数对板球运动员的数据进行排序。这qsort函数显示错误：

[错误] C:\Users\Encoder\Documents\C-Free\Temp\Untitled3.cpp:29: 错误：无效的转换int (*)(cricketer*, cricketer*) to int (*)(const void*, const void*)

[错误] C:\Users\Encoder\Documents\C-Free\Temp\Untitled3.cpp:29: 错误：初始化 `void qsort(void*, size_t, size_t, 整数（)(常量无效，常量无效*))'

include

#include<stdlib.h>
struct cricketer  //structure for details of cricketer
{
    int avg_run;
    char name[20];
    int age;
    int match_no;
} c[4];
int sort(struct cricketer *a, struct cricketer *b);   //pre-defining sort function 
int main()     //main function
{
    int i, s;
    for (i = 0; i < 3; i++)    //enumerating structure records.
    {
        printf("enter the name of cricketer ");
        fflush(stdin);
        gets(c[i].name);
        printf("enter his age,his no of matches and total average runs ");
        scanf("%d%d%d",&c[i].age, &c[i].match_no, &c[i].avg_run);
        }
    printf("records before sorting");  
    for (i = 0; i < 3; i++)
    {
        printf("\n\nname ");
        puts(c[i].name);
        printf("age %d\nno of matches %d\naverage runs %d\n",c[i].age, c[i].match_no, c[i].avg_run);
    }
    qsort(c, 3, sizeof(c[0]), sort); //sorting using qsort
    printf("\nrecords after sorting");
    for (i = 0; i < 3; i++)
    {
        printf("\n\nname ");
        puts(c[i].name);
        printf("age %d\nno of matches %d\naverage runs %d\n",c[i].age, c[i].match_no, c[i].avg_run);
    }
}
int sort(struct cricketer *a, struct cricketer *b)  //sort function definition
{
    if (a->avg_run == b->avg_run)
        return 0;
    else 
        if ( a->avg_run > b->avg_run)
            return 1;
        else 
            return -1;
}

您传递给其指针的函数qsort必须是

int sort(const void* va, const void* vb);

因为那就是qsort期望。然后在该函数中你必须从一开始就做

const struct cricketer *a = (struct cricketer*) va;
const struct cricketer *b = (struct cricketer*) vb;

或者如果您更喜欢使用点进行访问.而不是箭头->

const struct cricketer a = *(struct cricketer*) va;
const struct cricketer b = *(struct cricketer*) vb;

请参阅此处的示例参考

关于错误消息，这个int (*)(cricketer*, cricketer*)是一个指向函数的指针，该函数获取 2 个指向的指针cricketer作为参数。编译器期望这样的函数指针int (*)(const void, const void*)它告诉你它无法将前者转换为后者。另请注意，您如何需要指向 const 数据的指针，因为排序不应修改数据。