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;

}

Boa tarde galera estou com dificuldade de fazer esse trecho funcionar perfeitamente e ajudar.