Questions from Beginners MQL5 MT5 MetaTrader 5 - page 10

[Victor Kirillin]

mi__x__an:

with the function being universal,

You can't have a universal function.

[Михаил Янович]

Rosh:
Try to seeCComboBox class andEnumToString function. See also this articleCreate your own graphical panels in MQL5.

I've got that sorted out. The question was a bit different.

If theenum type exists and its components are unknown, is it possible to find them?

For example, there is theENUM_TIMEFRAME type

and our task is to find all the components of this type:{PERIOD_M1,PERIOD_M2...PERIOD_MN1} or{1,2...49153}

If you know all components of the type, you can implement a function that will return an array of possible values of theenum type. But is it possible to know the components of this type programmatically? For when creating newenum types we will have to write new functions of this kind, and it's not convenient.

Isn't there any possibility?

[Rashid Umarov]

mi__x__an:

uncleVic - Isn't there a single possibility???

No such possibility, software enumeration of all enumeration values is not implemented.

[Михаил Янович]

How many files can be opened at the same time?

By using this script :

   int f[];
   for (int i=0;i<1000;i++)
    {
     ArrayResize(f,i+1,0);
     f[i]=FileOpen(string(i)+".txt",FILE_WRITE|FILE_TXT,"\r\n");
     FileWrite(f[i],string(i));
    }

it was possible to find out that there are 64.

If so, is this information in the documentation? I haven't found it.

P.S.: Just came across - had to determine by experience the cause of the error. In my opinion such information could be added to the documentation.

P.S.S: I may be mistaken - then correct me.

[Yury Kulikov]

mi__x__an:

How many files can be opened at the same time?

By using this script :

it was possible to find out that there are 64.

If so, is this information in the documentation? I couldn't find any.

Runtime errors

ERR_TOO_MANY_FILES

5001

Cannot open more than 64 files at a time

[Михаил Янович]

Thanks for the correction. I LastError, forgot to check.

[Аrt]

Hello.

I have a little problem: I know MQL4, but I don't know MQL5. )))

Please help me to modify this code for MQL5.

double SpreadOnline;
string SMB; 

int init()
  {
   return(0);
  }

int deinit()
  {
   return(0);
  }

int start()
  {
   SMB=Symbol();
   SpreadOnline = NormalizeDouble(MarketInfo(SMB, MODE_SPREAD),0);

   Comment("Spread - ",SpreadOnline);

   return(0);
  }

[Olegs Kucerenko]

In the form of an expert:

double SpreadOnline=0.0;
string SMB=NULL; 

void OnInit()
  {
  
  }

void OnTick() // OnStart,OnCalculate
  {
   SMB=Symbol();
   
   SpreadOnline = NormalizeDouble(SymbolInfoInteger(SMB,SYMBOL_SPREAD),0);

   Comment("Spread - ",SpreadOnline);

  }
  
void OnDeinit(const int reason)
  {
   
  }

[Аrt]

Thank you! ))

[Kir7]

nemo811:
Thank you! ))

Gentlemen! Please answer me this question. I have installed the MT5 platform and opened a demo account on the metaquotes-demo server. My question is this. What is the time of the metaquotes-demo server? What is the situation with daylight saving time? If the change-over takes place as in England, then on the quotes history, the European time will start at the same time without any shifts. Am I thinking correctly? I am mainly interested in the history since January 2011.