51单片机按键控制多级菜单代码

以下是基于51单片机的按键控制多级菜单代码示例：

#include <reg51.h>

#define KEY_SCAN_INTERVAL 100

typedef struct MenuItem {
  char* name;
  unsigned char value;
  struct MenuItem* sub_menu;
} MenuItem;

MenuItem main_menu[] = {
  {"Option 1", 1, NULL},
  {"Option 2", 2, NULL},
  {"Option 3", 3, NULL},
  {"Submenu", 4, (MenuItem[]) {
    {"Suboption 1", 1, NULL},
    {"Suboption 2", 2, NULL},
    {"Submenu 2", 3, (MenuItem[]) {
      {"Subsuboption 1", 1, NULL},
      {"Subsuboption 2", 2, NULL},
      {NULL, 0, NULL}
    }},
    {NULL, 0, NULL}
  }},
  {NULL, 0, NULL}
};

unsigned char key_code = 0;

void main() {
  while (1) {
    key_code = read_key();
    if (key_code != 0) {
      unsigned char value = menu_select(main_menu);
      process_option(value);
    }
  }
}

unsigned char read_key() {
  // Read key code from hardware
}

unsigned char menu_select(MenuItem* menu) {
  unsigned char index = 0;
  while (1) {
    display_menu(menu, index);
    unsigned char key_code = read_key();
    if (key_code == KEY_UP) {
      if (menu[index - 1].name != NULL) {
        index--;
      } else {
        index = menu_length(menu) - 1;
      }
    } else if (key_code == KEY_DOWN) {
      if (menu[index + 1].name != NULL) {
        index++;
      } else {
        index = 0;
      }
    } else if (key_code == KEY_SELECT) {
      if (menu[index].sub_menu != NULL) {
        return menu_select(menu[index].sub_menu);
      } else {
        return menu[index].value;
      }
    } else {
      // Invalid key code, ignore
    }
    delay(KEY_SCAN_INTERVAL);
  }
}

void display_menu(MenuItem* menu, unsigned char index) {
  // Display menu on LCD with current selection highlighted
}

unsigned char menu_length(MenuItem* menu) {
  unsigned char length = 0;
  while (menu[length].name != NULL) {
    length++;
  }
  return length;
}

void process_option(unsigned char value) {
  // Handle selected menu option
}

这个代码示例定义了一个MenuItem结构体，包含菜单名称、对应的数值和子菜单列表。主菜单和子菜单都由MenuItem数组表示。在主循环中，读取按键输入，并通过menu_select函数选择菜单选项。menu_select函数递归地显示菜单，并根据按键输入选择当前菜单项或进入子菜单。display_menu函数在LCD上显示菜单，并使用当前选择项进行高亮显示。menu_length函数计算MenuItem数组的长度。最后，process_option函数处理选择的菜单选项。