C# « KYRIAKOS ANASTASAKIS – ΚΥΡΙΑΚΟΣ ΑΝΑΣΤΑΣΑΚΗΣ

During the past few months I have been creating some EAs in MQL5. I have also created some microservice like functions for other FinTech related projects (e.g. Market News / custom indicators). All those services are exposed with REST APIs. So there is the need to reuse this functionality from MQL5 Expert Advisors.

There are numerous examples in MQL5 that use WebRequest, however it’s not possible to use them from within backtesting. An error is raised in such cases. The other obvious alternative was to use a custom DLL that will be used from within MQL5 and delegate the REST call to the DLL.

In this direction I have created an opensource library rest-mql and an example on how to use it through MQL5. The library can be found here: https://github.com/cyrus13/rest-mql

The example MQL code can be found here: https://github.com/cyrus13/rest-mql/blob/master/mql5-sample-code/testmqldll.mq5

It is worth mentioning that REST calls certainly slow down the EA and should be used judiciously.

Recently I’ve been playing around with a webbrowser control to automate my interaction with a website for testing purposes. I am using C# and DOT NET.

I found it a bit difficult to change the value of an HTML combobox (i.e. dropdown), but as it turns out it’s rather easy.I used the following code to change the value of a combobox named: “test” to the value 12.

foreach (HtmlElement el in webBrowser1.Document.GetElementsByTagName("select"))
 {
 if (el.Name == "test")
 {
 foreach (HtmlElement comboItem in el.Children)
 {
 Console.WriteLine(comboItem.InnerText + " " + comboItem.GetAttribute("Selected"));
if (comboItem.InnerText == "12")
 {
 comboItem.SetAttribute("Selected", "True");
 }
 }
 }
}

This code was used for the following HTML:

<select name="test">
  <option value="10" SELECTED>10&</option>
  <option value="11">11</option>
  <option value="12">12</option>
  <option value="13">13</option>
  <option value="14">14</option>
</select>

Finally the following code was required to press the “Submit” button:

foreach (HtmlElement el in webBrowser1.Document.GetElementsByTagName("input"))
{
if (el.Name.ToLower() == "submit")
{
el.InvokeMember("click");
}
}

I recently wanted to get the usage of my CPU in C#. After searching the internet I found a way of doing it using the PerfomanceCounter class. I made a couple of changes and I created the following class, which seems to work.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;</code>

{
   public class SystemUtils
   {
      public static long getCpuUsage()
      {
        PerformanceCounter cpuCounter;
        cpuCounter = new PerformanceCounter();

        cpuCounter.CategoryName = "Processor";
        cpuCounter.CounterName = "% Processor Time";
        cpuCounter.InstanceName = "_Total";

        cpuCounter.NextValue();
        System.Threading.Thread.Sleep(1000);
        return (int) cpuCounter.NextValue();
      }
    }
}

Using the statement: SystemUtils.getCpuUsage() you should be able to get an integer number showing the CPU usage.

KYRIAKOS ANASTASAKIS – ΚΥΡΙΑΚΟΣ ΑΝΑΣΤΑΣΑΚΗΣ

Tag Archives: C#

Call REST endpoints from MQL5 during backtesting

Selecting the value of an HTML combobox programmatically using a WebBrowser Control

Getting the CPU Usage in C#