程序代码：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <conio.h>

struct menu_item
{
    char title[50];
    char key;
    void (*pf) (void);
};

int ShowMenu(const menu_item* menu);
void Fun1(void);
void Fun2(void);
void Fun3(void);
void Pause(void);

void main(void)
{
    const menu_item menu[] = {
        { "0.Exit", '0', 0 },
        { "1.Call Function1", '1', Fun1 },
        { "2.Call Function2", '2', Fun2 },
        { "3.Call Function3", '3', Fun3 },
        { "" }
    };

    int choice;
    do
    {
        choice = ShowMenu(menu);
        if (choice != 0)
        {
            menu[choice].pf ();
        }
    } while (choice != 0);
}

int ShowMenu(const menu_item menu[])
{
    system("CLS");
    for (int index = 0; strlen(menu[index].title) != 0; ++index)
    {
        printf_s("%s\n", menu[index].title);
    }
    printf_s("\nSelect: ");
    int choice = -1;
    do
    {
        int keypress = _getch();
        for (int index = 0; strlen(menu[index].title) != 0; ++index)
        {
            if (keypress == menu[index].key)
            {
                printf_s("%c\n\n", keypress);
                choice = index;
                break;
            }
        }
    } while (choice == -1);
    return choice;
}

void Fun1(void)
{
    printf_s("Now in Function1\n\n");
    Pause();
}

void Fun2(void)
{
    printf_s("Now in Function2\n\n");
    Pause();
}

void Fun3(void)
{
    printf_s("Now in Function3\n\n");
    Pause();
}

void Pause(void)
{
    printf_s("keypress any key to continue...");
    _getch();
}