Make an ARC Skill

Example: Custom EZ-Script Function

The EZ-Script engine has two event to add your own custom EZ-Script functions for users to use. The two different events will call before (Override) and after (Additional) the EZ-Script executor. That means you can either override existing commands or add new commands.

Additional Commands
Adding a command extends the existing commandset of EZ-Script. The example below demonstrates adding a new command to EZ-Script called "SetColor()".


SetColor(20, 100, 20)

The ExpressionEvaluation.FunctionEval.AdditionalFunctionEvent event is raised. Your plugin may attach to this event and process functions for the script.

Here is an example plugin that creates a user defined function called SetColor():


using System;
using System.Drawing;
using System.Windows.Forms;

namespace User_Defined_Function_Example {

public partial class FormMaster : EZ_Builder.UCForms.FormPluginMaster {

public FormMaster() {


private void FormMaster_Load(object sender, EventArgs e) {

// Intercept all unknown functions called from any EZ-Script globally.
// If a function is called that doesn't exist in the EZ-Script library, this event will execute
ExpressionEvaluation.FunctionEval.AdditionalFunctionEvent += FunctionEval_AdditionalFunctionEvent;

private void FormMaster_FormClosing(object sender, FormClosingEventArgs e) {

// Disconnect from the function event
ExpressionEvaluation.FunctionEval.AdditionalFunctionEvent -= FunctionEval_AdditionalFunctionEvent;

/// This is executed when a function is specified in any ez-scripting that isn't a native function.
/// You can check to see if the function that was called is your function.
/// If it is, do something and return something.
/// If you don't return something, a default value of TRUE is returned.
/// If you throw an exception, the EZ-Script control will receive the exception and present the error to the user.
private void FunctionEval_AdditionalFunctionEvent(object sender, ExpressionEvaluation.AdditionalFunctionEventArgs e) {

// Check if the function is our function (SetColor)
if (!e.Name.Equals("setcolor", StringComparison.InvariantCultureIgnoreCase))

// Check if the correct number of parameters were passed to this function
if (e.Parameters.Length != 3)
throw new Exception("Expects 3 parameters. Usage: SetColor(red [0-255], green [0-255], blue [0-255]). Example: SetColor(20, 200,100)");

// Convert the parameters to datatypes
byte red = Convert.ToByte(e.Parameters[0]);
byte green = Convert.ToByte(e.Parameters[1]);
byte blue = Convert.ToByte(e.Parameters[2]);

// Do something
EZ_Builder.Invokers.SetBackColor(label1, Color.FromArgb(red, green, blue));

// Return something. Good idea to return TRUE if your function isn't meant to return anything
e.ReturnValue = true;

Override Commands
Override commands will replace the existing EZ-Script command with your own version. This means you can intercept the command and handle the logic yourself. An example of this functionality is in the Ultrasonic Ping Sensor control, which replaces the GetPing() command with it's own version.

*Note: This event has OverrideFunctionEventArgs() which has a IsHandled(bool) that must be set if you hanlded the return object.

The ExpressionEvaluation.FunctionEval.OverrideFunctionEvent event and your logic must exist in there to override the existing command. If you expect a different number of parameters, you can still return and let the main EZ-Script handle it by not setting IsHandled in the OverrideFunctionEventArgs.


using ExpressionEvaluation;
using EZ_B;
using EZ_Builder.Config;
using EZ_Builder.Scripting;

namespace EZ_Builder.UCForms {

public partial class FormPing : FormMaster {

public FormPing() {


progressBar1.Maximum = EZ_B.HC_SR04.MAX_VALUE;

// Set the override event
ExpressionEvaluation.FunctionEval.OverrideFunctionEvent += FunctionEval_OverrideFunctionEvent;

private void FormPing_FormClosing(object sender, FormClosingEventArgs e) {

// detach from the override event
ExpressionEvaluation.FunctionEval.OverrideFunctionEvent -= FunctionEval_OverrideFunctionEvent;

private void FunctionEval_OverrideFunctionEvent(object sender, ExpressionEvaluation.OverrideFunctionEventArgs e) {

if (e.Name.Equals(OpCodeReadEnum.getping.ToString(), StringComparison.InvariantCultureIgnoreCase)) {

FunctionEval.CheckParamCount(e.Name, e.Parameters, 2);

string triggerStr = e.Parameters[0].ToString();
string echoStr = e.Parameters[1].ToString();
HelperPortParser cmdTrig = new HelperPortParser(triggerStr);
HelperPortParser cmdEcho = new HelperPortParser(echoStr);

if (cmdTrig.DigitalPort != _cf.Ping.PingTriggerPort ||
cmdTrig.BoardIndex != _cf.Ping.EZBIndex ||
cmdEcho.DigitalPort != _cf.Ping.PingEchoPort ||
cmdEcho.BoardIndex != _cf.Ping.EZBIndex)

if (!Invokers.GetCheckedValue(cbPause))

if (cmdTrig.BoardIndex != cmdEcho.BoardIndex)
throw new Exception("Trigger and Echo ports must be on the same EZ-B");

if (!EZBManager.EZBs[cmdTrig.BoardIndex].IsConnected)
throw new Exception(string.Format("Not connected to EZ_B {0}", cmdTrig.BoardIndex));

int value = EZBManager.EZBs[cmdTrig.BoardIndex].HC_SR04.GetValue(cmdTrig.DigitalPort, cmdEcho.DigitalPort);


e.ReturnValue = value;
e.IsHandled = true;


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Sorry but can I ask you something why I didn't see the ARC library when I added visual studio even though I set up the C ++. DLL library and there's another way to execute it and send / receive console in out but I don't know how to do it with EZ_builder?
#12   — Edited
Please follow the tutorial. It’s impossible to know why you’re plug-in isn’t showing up without asking you if you followed each step of the tutorial :). Reviewing your screenshots, it doesn’t appear as if any of the tutorial steps have been followed.
#13   — Edited
Hi i fixed it. thanks

Hello, I am trying the tutorial to get the robot to speak. I am using Visual studio. Currently, the sound is output from the pc instead of the robot. Is there a code I can attach so that the sound comes from the robot speakers instead of the pc?
#14   — Edited
Look in this tutorial for the step labeled "output audio from ezb". It’s lower down in the list. There’s instruction examples
for either playing audio (ie mp3) or text to speech.
Error: the referenced component" EZ_builder,EZ_B" could not be found, DJ Sure i hope you can help me !
#16   — Edited
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Joinny, you have to add the referencing by following the instructions in this tutorial. They are outlined with step by step to easily follow. Click add references, and browse to the appropriate files as directed in the tutorial. I can’t write anything clearer in response. The step to add references is incredibly clear but you’re skipping it.
The error cannot read the COM file, I downloaded it and when I follow the instructions, I get an error, while other files read normally.
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#18   — Edited
sorry for me but i tried many different ways but still show the error,I couldn't find EZ_B.dll file even though I downloaded it
None of the required references are in your list. Please follow the tutorial. It explains exactly how to click the browse button and navigate to the folder and select the files.
Sorry, but the reason I can't reference is because there is no file in the EZ_B folder and there is an error : this folder is empty , I am trying to solve it. I would like to thank DJ sure for answering my superfluous questions and I'm sorry for bothering you
#21   — Edited
I need to playback 5 Serial Bus servos in sequence.
#22   — Edited
What protocol is it? A "serial bus" is a generic term for anything using a UART that's chained together sharing the same RX line. Also, why did you add a photo with the question text added in your response?

Are you planning on making a skill control to do this? You wrote the question in the skill control thread in a comment - I'd like to make sure your question is in the right place to help you out.

To begin, I would recommend starting with servo Script control so you can make the serial bus protocol work - then consider making a skill control only if you're planning on distributing the effort to others:
He seems rather demanding as well.  I guess he needs the benefit of the doubt as English may not be his native language....
#24   — Edited
I have installed all the software dependencies and still ARC does not detect that I have Visual Studio installed.
OS is Windows 10, .NET 4.8 or newer, Visual Studio Community 2019.
When the popup says it doesn’t detect visual studio, you can still skip and continue. I wonder why it’s not detecting it? We had a hard time trying to find a proper way of detecting - even Microsoft’s suggestion didn’t actually work *eye roll*

ill look into it a bit further and see if we can find a better way of detecting
It's easy to find the Visual Studio 2017 and up:

Some quick c# code to use with .NET:


using System;
using System.Diagnostics;
using System.IO;

namespace FindVisualStudio
internal class Program
static string ProcessStart(string fileName, string args)
var processStartInfo = new ProcessStartInfo
Arguments = args,
CreateNoWindow = true,
FileName = fileName,
RedirectStandardOutput = true,
UseShellExecute = false,
WindowStyle = ProcessWindowStyle.Hidden,
WorkingDirectory = Path.GetDirectoryName(fileName),

using (var process = Process.Start(processStartInfo))
return process.StandardOutput.ReadToEnd().Trim();

private static string GetInstallationPath(string vsWhere)
var installationPath = ProcessStart(vsWhere, "-latest -products * -requires Microsoft.Component.MSBuild -property installationPath");
return installationPath;

private static string GetProductLineVersion(string vsWhere)
var version = ProcessStart(vsWhere, "-latest -property catalog_productLineVersion");
return version;

private static void Main(string[] args)
var programFiles = Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86);
var vsWhere = Path.Combine(programFiles, "Microsoft Visual Studio", "Installer", "vswhere.exe");
if (!File.Exists(vsWhere))
throw new FileNotFoundException("Cannot find Microsoft Visual Studio's vswhere.exe utility.", vsWhere);

var version = GetProductLineVersion(vsWhere);
Console.WriteLine($"Visual Studio Version: {version}");

var installationPath = GetInstallationPath(vsWhere);
if (!Directory.Exists(installationPath))
throw new DirectoryNotFoundException(installationPath);

Console.WriteLine($"Visual Studio installation Path: {installationPath}");

#27   — Edited


With Visual Studio 2017 Update 2 or newer installed, you can find vswhere at %ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe, or to make sure it's always available in your repo see Installing for an option using NuGet.
Because is only available with "Visual Studio 2017 Update 2", you can add the vswhere package to your ARC project, and use your version (nuget) to detect older 2017 or legacy Visual Studio Versions (although does not make sense for ARC).
#28   — Edited
We went this route and it didn’t work on my computer - because I had a preview of visual studio installed which isn’t in that directory path. Microsoft had numerous suggestions of detecting visual studio. The one which worked for our various installations was a registry check. 

apparently with the above individual, the registry didn’t work either. I’ll have to combine a few methods.

everything looks simple from the outside - until you have a hundred thousand+ installations of your software. That’s when you run into things like this lol
#29   — Edited
I agree sometimes the things go out of script easily.

I avoid going through the registry keys, unless is recommended by the vendor.
A lot of people blame the changes (keys,  entries are renamed etc), but, that is normal if I own my product is my business and is part of the software evolution. Some products you can break the support contract agreement if you query directly the database, or if you look elsewhere outside of the public API.

Is true story some years ago a "rogue" developer on my team released a Sharepoint integration using a mix of APIs and database queries, everything worked well with multiple clients, until one day the Microsoft Black suits visit one of the customers to follow up on an unrelated support ticket, and they basically used "unsupported" card and left the client hanging, and we had problems too, unfortunately the Rogue developer went to another galaxy ... and the team suffered the consequences.   

That does not mean I'm not tempted to do it...:) 

I used the vswhere before and I would say is almost 99% bulletproof, is used with Xamarin, NVIDIA, Intel setups. If you add vswhere.exe to your project (nuget package) you cover scenarios where the tool is not present or have been deleted (broken uninstalls). 

The other fallback could be ask the user the visual studio version.

The other reason to avoid registry is due to Visual Studio uses a private exclusive registry keys to store more stuff:

So the things are getting more complex.

The above post is only part of the "Full solution" for example I have one setup with visual studio 2017 c# installed and Visual studio 2019 with Python and C++, vswhere will return 2019 version,  but my c# is done with VS2017.

If you are generating customized vs version project files, maybe a fallback (ask the VS version) will cover more bases.
Yes - Microsoft has a few pages on how to identify visual studio and we tried them all during testing - the one we went with was with registry. I'm going to combine the two as using only one method apparently doesn't work for all cases.