external variables : choosing in a list of choices

New comment
 

hi!

when you use extern variables, its often to input a number or to set a bool true or false. in my case, id prefer to let the user choose between some options, like a menu. so i would like to define the different possibilities he'll be able to choose, like a string that allows only 3 possibilities. i've never saw anything like this in the doc or in any mq4 file, but i suppose its not hard to set up for a skilled mql developper...so, could anyone help?

 

u can do something like this

//+------------------------------------------------------------------+
//|                                               user_selection.mq4 |
//|                      Copyright © 2010, MetaQuotes Software Corp. |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2010, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net"

#include <WinUser32.mqh>

bool something;
//+------------------------------------------------------------------+
//| expert initialization function                                   |
//+------------------------------------------------------------------+
int init()
  {
//----
   int ret=MessageBox("Select The value for something \n\nOK = true \nCANCEL = false \n
   \n\"NOTE\" Pressing ESC Or X = false", "Question", MB_OKCANCEL|MB_ICONQUESTION);
   if (ret == IDOK)
      {
      something = true;
      }
   if (ret == IDCANCEL)
      {
      something = false;
      }
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| expert deinitialization function                                 |
//+------------------------------------------------------------------+
int deinit()
  {
//----

//----
   return(0);
  }
//+------------------------------------------------------------------+
//| expert start function                                            |
//+------------------------------------------------------------------+
int start()
  {
//----

   if (something)
      //do x

   if (!something)
      //do y

//----
   return(0);
  }
//+------------------------------------------------------------------+
 

yes it can be a way to make something with interactivity...but i explained myself wrong : i just want to be able to browse in a list of things before running a backtest, so this would be trough an ext variable, in the ea setup menu...

maybe it will be clearer like this :


there are ext variables like


ext bool blabla = true;

and you can choose true or false...in a scrolling list. this is the scrolling list i want to customize!


so i would like something like

ext string currency = "eurusd" OR "eurjpy" OR "eurgbp"

leading to a list of possibilities before running a backtest!

 

FWIW I use the following method for picking which price to use. Could be changed to Pair1EURUSD_2EURJPY_3EURGBP

extern int Price_0COHLMedTypWgt6=PRICE_TYPICAL;
New comment