C语言-观察者模式

#include <stdio.h>

#define MAX_OBSERVERS 10        

typedef struct Observer{
    int Oberver_value;
    void (*update)(struct Observer *observer, int value);
}Observer;

typedef struct Subject{
    int value;
    Observer *observes[MAX_OBSERVERS];      
    int observeCount;
}Subject;

void updateFunction(Observer *observer, int value) 
{
    observer->Oberver_value = value;
    printf("Observer have updated with value: %d\n", observer->Oberver_value);
}


void registerObserver(Subject *subject, Observer *Observer)
{
    if(subject->observeCount < MAX_OBSERVERS)
    {
        subject->observes[subject->observeCount++] = Observer;
    }
}

void notifyObservers(Subject *subject)
{
    for(int i = 0; i < subject->observeCount; i++)
    {
        subject->observes[i]->update(subject->observes[i],subject->value);
        //subject->observes[i]->Oberver_value = subject->value;
        //printf("Observer[%d] updated with value: %d\n",i+1,subject->observes[i]->Oberver_value);
    }
}

void  setValue(Subject *subject, int value)
{
    subject->value = value;
    notifyObservers(subject);
}


int main()
{
    
   Subject subject1;                          //被观察者

   subject1.value = 0;
   subject1.observeCount = 0;

   Observer observer1;                        //观察者
   observer1.update = updateFunction;
   Observer observer2;                        //观察者
   observer2.update = updateFunction;
   Observer observer3;                        //观察者
   observer3.update = updateFunction;


   registerObserver(&subject1, &observer1);  //注册观察者
   registerObserver(&subject1, &observer2);  //注册观察者
   registerObserver(&subject1, &observer3);  //注册观察者

   setValue(&subject1,100);                  //设置被观察者的值，并内存通知、更新观察者的值 

      

   return 0;
}