如何定义定义结构指针和下面提到的格式。以及如何在代码中访问 .servicefunc？

Question

CONST(Student_ServiceCfgType, VAR) student[] =
{
    {&Student_Name,    NAME},
    {&Student_age,  AGE}
};

main_function()
{
   /* get the Service index of the Service Configuration table */
    Student_Service =  0; // takes 0th element from above config table.

    /* Send the service */
    status = (*student[Student_Service].ServiceFunc)();

    /* notify application about service finish */
    status = Student_UsrCallback(student[Student_Service].ServiceType, status);
}

struct
{
}Student_ServiceCfgType;


status = (*student[Student_Service]***.ServiceFunc***)();

问题1）请解释一下上面这行代码是什么意思？

Q2) 可以解释上面的代码是如何工作的

Answer 1

1.请解释一下上面这行代码是什么意思？

ServiceFunc 是指向函数的指针，它保存 returns status 类型的函数的地址并且不带参数。

So overall your struct student might look like below.

typedef struct
{
  status (*ServiceFunc)(); //declaring function pointer
}studentStruct;

And you function might look like below.

status func1()
 {
      status ret = 0;
      printf("studenti\n");
      return ret;
 }

And you assign the function pointer and call the function using function pointer as below.

studentStruct student[1];
student[0].ServiceFunc = &func1;

status st = (*student[0].ServiceFunc)();

这正是您在这里所做的。

status = (*student[Student_Service].ServiceFunc)();

Your complete code might look like below.

#include<stdio.h>
typedef int status;

typedef struct
{
  status (*ServiceFunc)();
}studentStruct;


status func1()
{
  printf("studenti\n");
  return 0;
}

int main()
{
 studentStruct student[10];
 student[0].ServiceFunc = &func1;

status st = (*student[0].ServiceFunc)();

return 0;
}

如何定义定义结构指针和下面提到的格式。以及如何在代码中访问 .servicefunc？

how to define define structure pointer and below mentioned format. and how to access .servicefunc in code?

c

pointers

structure