[C51 code] Menu function [for LCD1602]

#define __menu_h__
#include "head.h"
#include "LCD1602_2.h"
#include "DS18B20.h"

#define Null 0

/***********************

* Function declaration *

***********************/

void ShowMenu(void);

void Menu_Change(volatile KeyNum);

/***********************

* Key function key macro definition *

***********************/

#define up    1

#define down  2

#define back  4

#define ok    5

/**********************

* Directory structure definition *

**********************/

struct MenuItem

{

   uchar MenuCount; //Number of nodes in the current layer

   uchar *DisplayString; //Menu title

   void (*Subs)(); //Node function

   struct MenuItem *ChildrenMenus; //child nodes

   struct MenuItem *ParentMenus; //parent node

};

/*********************** 
* Call sub-function area * 
***********************/ 
void NullSubs(void) 
{

 }

/***********************

* Structure area *

***********************/
struct MenuItem NameMenu[2];

struct MenuItem NumberMenu[2];

struct MenuItem MainMenu[3];

struct MenuItem NameMenu[2]=

{ //MenuCount   DisplayString    Subs            ChildrenMenus     ParentMenus

   {2, "WeiMen", NullSubs, Null, MainMenu},

   
   {2,                    "Back",            NullSubs,      MainMenu,          MainMenu},

};

struct MenuItem NumberMenu[2]=
{ //MenuCount       DisplayString     Subs          ChildrenMenus     ParentMenus

   {2,                      "0500320128",   NullSubs,   Null,                       MainMenu},

   
   {2,                       "Back",              NullSubs,   MainMenu,            MainMenu},

};
struct MenuItem MainMenu[3]=

{ //MenuCount   DisplayString              Subs          ChildrenMenus      ParentMenus

   {3,                   "1.Show Name ",        NullSubs,    NameMenu,           Null},
      
   {3,                    "2.Show Number",     NullSubs,   NumberMenu,       Null},

   {3,                    "3.Back",        MainMenu,         MainMenu},

};

/***********************

* Global variable declaration area *

***********************/

struct MenuItem (*MenuPoint) = MainMenu; //Structure pointer, after pointing to the structure, the internal function pointer points to the function function

uchar DisplayStart = 0; //The first menu item when displayed

uchar UserChoose = 0; //Menu item selected by the user

uchar DisplayPoint = 0; //display pointer

uchar MaxItems; //Maximum number of menus at the same level

uchar ShowCount=2; //Number of menus displayed on the same screen

/***********************

*Show function area*

***********************/

void ShowMenu(void)  
{ 
  unsigned char n; 
MaxItems = MenuPoint[0].MenuCount;//定义最大同级菜单 
DisplayPoint = DisplayStart; 
for(n=0;DisplayPoint   {if(DisplayPoint==UserChoose) 
  LCDDispListChar(0,n,"->");
  LCDDispListChar(2,n,MenuPoint[DisplayPoint++].DisplayString);
   
  }

}

void Menu_Change(unsigned char KeyNum) 
{ 
if(KeyNum) 
{ 
  switch(KeyNum)  
  {      
    case up:  
    UserChoose --;  
    if (UserChoose == 255) 
    {  
      UserChoose = 0;//Upward limit, if you want to roll back, assign the value to MaxItems-1 
    }  
    break;  
    case down:  
    UserChoose ++;  
    if (UserChoose == MaxItems)  
    {  
      UserChoose = MaxItems-1;//Downward limit, if you want to roll back, assign the value to 0  
    }  
    break;
 case back:
 if (MenuPoint[UserChoose].ParentMenus != Null) 
  { 
    MenuPoint = MenuPoint[UserChoose].ParentMenus; 
    UserChoose = 0; 
    DisplayStart = 0; 
  } 
  break;              
 case ok:  
     if (MenuPoint[UserChoose].Subs != NullSubs) 
        { 
          (*MenuPoint[UserChoose].Subs)(); 
        } 
        else if (MenuPoint[UserChoose].ChildrenMenus != Null) 
        { 
          MenuPoint = MenuPoint[UserChoose].ChildrenMenus; 
          UserChoose = 0; 
          DisplayStart = 0; 
        } 
        break;

       default:break; 
  } 
  if (UserChoose%ShowCount==0) //Only ShowCount rows can be displayed on one screenDisplayStart 
  = UserChoose; 
  else if(UserChoose==1||UserChoose== 3) 
    DisplayStart = UserChoose-1; //The key to scrolling    
    LCDWriteCmd(DispClear); //Clear the LCD screen, modify it according to different LCD functions 
    delay1ms(2); //LCD is a slow device 
    ShowMenu();  
} 
}

#endif