c语言switch结构多次用,多SWITCH-CASE结构时的C语言对象方式化解

原有代码：

#include

int main()

{

int n=0;

while(1)

{

scanf("%d",&n);

switch(n)

{

case 0:

printf("STATE0\n");

break;

case 1:

printf("STATE1\n");

break;

case 2:

printf("STATE2\n");

break;

default:

return 0;

}

}

return 0;

}

改造方案：

#include

#define N 3 //状态值

struct State

{

int i;

void (*CreateState)(struct State *s);

void (*Show)(struct State s);

void (*StateTrans[N])(struct State s);

};

void StateTrans0(struct State s)

{

s.i=0;

s.Show(s);

}

void StateTrans1(struct State s)

{

s.i=1;

s.Show(s);

}

void StateTrans2(struct State s)

{

s.i=2;

s.Show(s);

}

void Show(struct State s)

{

printf("State-%d\n",s.i);

}

void CreateState(struct State *s)

{

s->Show=Show;

s->StateTrans[0]=StateTrans0;

s->StateTrans[1]=StateTrans1;

s->StateTrans[2]=StateTrans2;

}

enum{ST0=0,ST1,ST2}STATE;//枚举状态

int main()

{

State s;//实例化

//初始化

s.CreateState=CreateState;

s.CreateState(&s);

//模拟状态调用

while(1)

{

scanf("%d",&STATE);

if(STATE<0||STATE>2)

{

break;

}

s.StateTrans[STATE](s);

}

getchar();

return 0;

}