将struct传递给另一个.c文件中的函数，但它不指向正确的struct

Question

I am trying to pass a struct to a function, but the function I am passing the struct to, is located inside another .c file.

When I run debug, the struct's address in the other file is different, thus the variables don't get updated within the receiving function. The reason I do it this way is because I have various menus in my program and I want to have a separate file for each menu.

inside defs.h file

typedef struct{ 
    byte min;       
    byte max;       
}menuOptionValue_s;

inside menu.h file

void draw_menuOption(menuOptionValue_s);

inside menu.c file

#include "defs.h"
#include "menu.h"

void draw_menuOption(menuOptionValue_s menu){
     byte value = menu.max;
     draw(x,y,value);
}

inside settings.c file

#include "defs.h"
#include "menu.h"
void setting_Init(void);
menuOptionValue_s setting;
menuOptionValue_s second_setting;

void setting_Init(void){
     setting.max = 10;
     setting.min = 1;
     second_setting.max = 20;
     second_setting.min = 11;
     draw_menuOption(setting);
     draw_menuOption(second_setting);
}

I want to be able to call draw_menuOption() from any .c file and pass structs within those .c files The code I provided is significantly shrank, the setting_Init() is called once in the main.c and draw_menuOption(setting) is called from within a different function inside a setting.c , I just wanted to show that I am actually calling it.

Answer 1

You're passing the object by value . That means a copy is made.

Pass a reference or pointer if you want to affect the original object.

This topic should be covered early on in your book.