#import questions

TheExponential · #1 (**permalink**) 12-04-2005, 11:11 PM

I'm trying to create a library file (.ex4) file to be used by #import syntax in the main program.

I have a problem in compiling the called library program. when trying to compile it, it complains "Start function not found". What should I do?

Should I also put these library programs in a separate directory?

Thanks!

TheExponential · #2 (**permalink**) 12-06-2005, 10:08 PM

can anyone help, please!

CodesGuru?

codersguru · #3 (**permalink**) 12-06-2005, 11:48 PM

Quote:

Originally Posted by TheExponential

I'm trying to create a library file (.ex4) file to be used by #import syntax in the main program.

I have a problem in compiling the called library program. when trying to compile it, it complains "Start function not found". What should I do?

Should I also put these library programs in a separate directory?

Thanks!

TheExponential,
I'm so sorry for the delay.

The error you have got because (I think) you didn't write this line on the top of your library program:

#property library
To create a library you have to:

1- Use #property library preprocessor directive on the top of your program (see the example).

2- Compile and save it in "MetaTrader 4\experts\libraries" path.

Example:

PHP Code:


			
//+------------------------------------------------------------------+
//|                                                     Alerts.mq4 |
//|                                                     Coders Guru |
//|                                         http://www.forex-tsd.com |
//+------------------------------------------------------------------+

//+------------------------------------------------------------------+
//|Use this code at your risk, I don't guarantee anything.         |                                     |
//+------------------------------------------------------------------+
#property copyright "Coders Guru"
#property link      "http://www.forex-tsd.com"
#property library
#include <WinUser32.mqh> //for MessageBoxA

#import "kernal32.dll"


//+------------------------------------------------------------------+
//|This function shows dialog box showing the data you passed        | 
//|Click "Retry if you want to see the messages next time,           | 
//|and click "Cancel" to disable the messages                     |                                     |
//+------------------------------------------------------------------+
void Msg(string message)
{
   //int MessageBoxA(int hWnd ,string lpText,string lpCaption,int uType);
   static bool disable = false;
   int result = 0;
   
   if(!disable)
   result = MessageBoxA(NULL,message,"Click cancel to disable Alerts!",MB_RETRYCANCEL|MB_ICONINFORMATION);
   
   if(result==IDCANCEL)
   disable=true;  
}

//+------------------------------------------------------------------+
//|This function rerun trus when line1 cross line2                 |
//|and false otherwise                                             | 
//|Ex: Print(Crossed (ExtMapBuffer1[0],ExtMapBuffer2[0]));           | 
//+------------------------------------------------------------------+
bool Crossed (double line1 , double line2 )
{

static string last_direction = "";
string current_dirction = "";

if(line1>line2)current_dirction = "up";
if(line1<=line2)current_dirction = "down";



if(current_dirction != last_direction) 
{
      //Alert("EMA Cross for "+Symbol()+" on the "+Period()+" minute chart.");
      Msg("EMA Cross for "+Symbol()+" on the "+Period()+" minute chart.");
      last_direction = current_dirction;
      return (true);
}
else
{
      return (false);

}
 
} 

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

TheExponential · #4 (**permalink**) 12-08-2005, 10:45 AM

Thanks once again, CodesGuru. I'll give it a try!

TheExponential · #5 (**permalink**) 12-09-2005, 04:53 AM

I have been able to compile the Library, but it fails in the import.

I have called my library program TELib.mq4. I've compiled and put it in the library path.

in using it, I wrote #import "TELib.ex4". And ends it with empty #import statement.

but it still complains when I refer to functions in the import.

Thanks.

TheExponential · #6 (**permalink**) 12-09-2005, 04:56 AM

I've also failed to use the standard stdlib.ex4 that MetaQuotes provides.

I tried to access ErrorDescription function, and it complains that the function is not defined.

Thanks again

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
#import	charliev	Metatrader 4	8	04-06-2008 07:07 AM
2 questions on codergurus course	hayseed	Setup Questions	3	12-07-2006 10:56 PM
Import custom DLL	The_N	Expert Advisors - Metatrader 4	1	05-30-2006 09:09 PM
MT3 Questions	Nicholishen	Metatrader 3	1	02-01-2006 03:10 PM

Register in Forex TSD!
Trading Systems Leaders in this forum (automated trading systems) are winning more than 3000 pips in a month (30000$ investing one lot every time). Click here to register and get more information