Dll, write by Borland Delphi. Can't work in MT5.

[Jun Yuan]

dll file ================================

library TestDll;

uses
  ShareMem, SysUtils, Classes;

  function TestDll_A(i: integer): integer; stdcall;
  begin
    Result := i * 100;
  end;
  function TestDll_B(aStr: PChar): integer; stdcall;
  begin
//    StrCopy(aStr, PChar('123'));

    StrCopy(aStr, PChar('in dll in dll'));

    Result := 0;
  end;

exports
  TestDll_A, TestDLL_B;

{$R *.res}

begin

end.

 

mt5 file ================================

//+------------------------------------------------------------------+
//|                                                      TestDll.mq5 |
//|                        Copyright 2010, MetaQuotes Software Corp. |
//|                                              http://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "2010, MetaQuotes Software Corp."
#property link      "http://www.mql5.com"
#property version   "1.00"

#import "TestDll.dll"
  int TestDll_A(int i);
  int TestDll_B(string &aStr);
#import


//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+
int OnInit()
{
//---
   string te = "MQL5 string MQL5 string";
   Print("123456789");
   Print(TestDll_A(30));
   Print("123456789");     
   TestDll_B(te);
   Print(te);
   Print("123456789");     
//---
   return(0);
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
//---
  
  }
//+------------------------------------------------------------------+
//| Expert tick function                                             |
//+------------------------------------------------------------------+
void OnTick()
  {
//---
  
  }
//+------------------------------------------------------------------+

=============================================

When I was in borland Delphi to call this DLL, can show normal, when I MT5 were called, only showed non-normal character.

How can I do? Thanks!

[Ilyas]

About string type (link)

The string type is used for storing text strings. A text string is a sequence of characters in the Unicode format with the final zero at the end of it.A string constant can be assigned to a string variable. A string constant is a sequence of Unicode characters enclosed in double quotes: "This is a string constant".

[Jun Yuan]

mql5:

About string type (link)

 Thanks, I will try, I do renounce the use of DLL, only in the MT5 in string handling.