How to useTrade.mqh library in mql5?

[Yule Msee]

#include <Trade\Trade.mqh>

CTrade trade;

I am new to mql. I have seen the code above in *** but there are parts I do not understand. 

I understand the first line. We are importing the Trade header file from the Trade.mqh library.

What does the second line mean? Are we assigning the CTrade class to a variable named 'trade' ? And

where does the CTrade value come from. Is it from the first line? If so how does the CTrade gets its value from

the first line?

When we include a library in mql how do we get to access its functions and other values?

[Paul Anscombe]

Yule Msee:

#include <Trade\Trade.mqh>

CTrade trade;

I am new to mql. I have seen the code above in this tutorial but there are parts I do not understand. 

I understand the first line. We are importing the Trade header file from the Trade.mqh library.

What does the second line mean? Are we assigning the CTrade class to a variable named 'trade' ? And

where does the CTrade value come from. Is it from the first line? If so how does the CTrade gets its value from

the first line?

When we include a library in mql how do we get to access its functions and other values?

try this   https://www.mql5.com/en/articles/481

[Vladimir Karputov]

Example:

 //+------------------------------------------------------------------+ 
 //|                                                     Open Buy.mq5 | 
 //|                              Copyright © 2018, Vladimir Karputov | 
 //+------------------------------------------------------------------+ 
 #property  copyright "Copyright © 2018, Vladimir Karputov" 
 #property  version    "1.000" 
 //--- 
 #include  <Trade\Trade.mqh>
CTrade         m_trade;                       // object of CTrade class 
 //+------------------------------------------------------------------+ 
 //| Script program start function                                    | 
 //+------------------------------------------------------------------+ 
 void OnStart ()
  {
 //--- 
   m_trade.Buy( 1.0 ); // open Buy position, volume 1.0 lot 
  }
 //+------------------------------------------------------------------+ 

We connect a trading class:

 #include  <Trade\Trade.mqh>

We declare the object ( m_trade ) of the trade class CTrade

CTrade         m_trade;                       // object of CTrade class 

after that, through the m_trade object , we get access to the public methods of the CTrade trading class (in the example below, we turn to the 1.0 Open BUY Position method)

   m_trade.Buy( 1.0 ); // open Buy position, volume 1.0 lot 

[Deivitti Almir Rodrigues Batista]

double CalcularAssertividade()
{
   int totalDeals = HistóricoDealsTotal();
   int ofertas vencedoras = 0 ;
   
   para( int i = 0 ; i < totalDeals; i++)
   {
      se(HistóricoDealSelect(i))
      {
         se(HistoryDealSymbol() == _Symbol && HistoryDealMagic() == MagicNumber)
         {
            se(HistóricoProfit() > 0 )
            {
               ofertas vencedoras++;
            }
         }
      }
   }

   se(totalDeals == 0 ) retornar 0 , 0 ;

   retornar (duplo(ofertas vencedoras) / totalOfertas) * 100 , 0 ;
}

Good afternoon everyone, I'm having trouble making this section work perfectly and help.

[Thabo Modiba]

I Can some1 please assist me with the corrections...

//+------------------------------------------------------------------+

//|                    CoDaC ZigZag EA                              |
//|      Integrates with CoDaC ZigZag Arrows Duplex MT5 Indicator  |
//+------------------------------------------------------------------+
#include <Trade/Trade.mqh>
CTrade trade;

// Indicator handles
int zigzagHandle;

// Buffers
double slowZigzagBuffer[];
double fastZigzagBuffer[];

// Indicator Parameters
input string IndicatorName = "CoDaC ZigZag Arrows Duplex MT5";
input int IndicatorSlowBuffer = 0;
input int IndicatorFastBuffer = 1;

//+------------------------------------------------------------------+
//| Expert initialization function                                  |
//+------------------------------------------------------------------+
int OnInit()
{
    Print("Initializing EA...");
    
    zigzagHandle = iCustom(Symbol(), PERIOD_CURRENT, IndicatorName);
    
    if (zigzagHandle == INVALID_HANDLE)
    {
        Print("Error loading indicator: ", IndicatorName);
        return INIT_FAILED;
    }
    else
    {
        Print("Indicator successfully loaded: ", IndicatorName);
    }
    
    return INIT_SUCCEEDED;
}

//+------------------------------------------------------------------+
//| Expert deinitialization function                                |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
{
    Print("Deinitializing EA...");
    IndicatorRelease(zigzagHandle);
}

//+------------------------------------------------------------------+
//| Function to close all trades                                     |
//+------------------------------------------------------------------+
void closeAllTrades()
{
    for (int i = PositionsTotal() - 1; i >= 0; i--)
    {
       #include <Trade.mqh>

CTrade trade;

int OnInit()
{
    Print("Initializing EA...");
    return INIT_SUCCEEDED;
}

void OnTick()
{
    for(int i = PositionsTotal() - 1; i >= 0; i--)
    {
        if(PositionSelect(i))  // Corrected from PositionSelectByIndex
        {
            long ticket = PositionGetInteger(POSITION_TICKET);  // Corrected from PositionGetTicket(index)
            Print("Position Ticket: ", ticket);
        }
    }
}

[Conor Mcnamara]

Thabo Modiba #:
void closeAllTrades() {     for (int i = PositionsTotal() - 1; i >= 0; i--)     {        #include <Trade.mqh> CTrade trade; int OnInit() {     Print("Initializing EA...");     return INIT_SUCCEEDED; }

void closeAllTrades()
{
    for (int i = PositionsTotal() - 1; i >= 0; i--)
    {
       #include <Trade.mqh>

CTrade trade;

int OnInit()
{
    Print("Initializing EA...");
    return INIT_SUCCEEDED;
}

can't you see the problems here...?

I use PositionSelectByTicket to directly modify the open positions

https://www.mql5.com/en/docs/trading/positionselectbyticket

if(PositionSelectByTicket(  PositionGetTicket(i) )){

//

}

PositionSelect takes a symbol name, not an index

https://www.mql5.com/en/docs/trading/positionselect

Maybe you should study the reference and read articles on building EAs