How to Debug a cBot¶

cTrader allows developers to create, modify or work with algorithms through its built-in editor. However, some developers are already familiar with a different environment or might prefer working in a professional IDE.

In this article and its corresponding video, we will demonstrate how you can debug a cBot in Visual Studio.

Open a cBot in Visual Studio¶

Go to the 'Algo' app in cTrader and navigate to the 'cBots' tab. For demonstration purposes, let's debug the 'Sample RSI cBot'.

Locate 'Sample RSI cBot' and click it. The code editor should appear on the right.

Click 'Edit in Visual Studio'. If you have Visual Studio installed on your machine, it should open the cBot code.

Enable Debugging in Visual Studio¶

If the code editor in Visual Studio does not automatically show the cBot code, you have to locate and click the C# (.cs) file in the 'Sample RSI cBot' solution.

Select the 'Debug' configuration mode.

Now, you have to modify the cBot code to allow debugging.

Start by setting the cBot AccessRights to FullAccess.

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[Robot(TimeZone = TimeZones.UTC, AccessRights = AccessRights.FullAccess, AddIndicators = true)]

Attach a debugger to the cBot running process by calling the System.Diagnostics.Debugger.Launch() method.

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var result = System.Diagnostics.Debugger.Launch();

if (result is false)
{
    Print("Debugger launch failed");
}

At this point, the code in your Visual Studio code editor should look like this:

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using cAlgo.API;
using cAlgo.API.Indicators;

namespace cAlgo
{
    [Robot(TimeZone = TimeZones.UTC, AccessRights = AccessRights.FullAccess, AddIndicators = true)]
    public class SampleRSIcBot : Robot
    {
        [Parameter("Quantity (Lots)", Group = "Volume", DefaultValue = 1, MinValue = 0.01, Step = 0.01)]
        public double Quantity { get; set; }

        [Parameter("Source", Group = "RSI")]
        public DataSeries Source { get; set; }

        [Parameter("Periods", Group = "RSI", DefaultValue = 14)]
        public int Periods { get; set; }

        private RelativeStrengthIndex rsi;

        protected override void OnStart()
        {
            var result = System.Diagnostics.Debugger.Launch();

            if (result is false)
            {
                Print("Debugger launch failed");
            }

            rsi = Indicators.RelativeStrengthIndex(Source, Periods);
        }

        protected override void OnTick()
        {
            if (rsi.Result.LastValue < 30)
            {
                Close(TradeType.Sell);
                Open(TradeType.Buy);
            }
            else if (rsi.Result.LastValue > 70)
            {
                Close(TradeType.Buy);
                Open(TradeType.Sell);
            }
        }

        private void Close(TradeType tradeType)
        {
            foreach (var position in Positions.FindAll("SampleRSI", SymbolName, tradeType))
                ClosePosition(position);
        }

        private void Open(TradeType tradeType)
        {
            var position = Positions.Find("SampleRSI", SymbolName, tradeType);
            var volumeInUnits = Symbol.QuantityToVolumeInUnits(Quantity);

            if (position == null)
                ExecuteMarketOrder(tradeType, SymbolName, volumeInUnits, "SampleRSI");
        }
    }
}

Let's rebuild our cBot. Right-click the 'Sample RSI cBot' solution and click 'Rebuild'.

Debug the cBot¶

To demonstrate the debugging process, let's add a breakpoint in our OnTick() method. Right-click the if (rsi.Result.LastValue < 30) line of code, click 'Breakpoint' and then select 'Insert Breakpoint'.

Now, you have to go back to 'Sample RSI cBot' in cTrader. Click 'Add instance'.

Select 'Locally' and then click the 'Add instance' button.

Click the Start cBot icon to run the cBot, then click the 'Allow' button to grant it access rights.

Select the 'Sample RSI cBot - Microsoft Visual Studio' as your debugger and click the 'OK' button.

On reaching the OnTick() event, the execution breaks by the breakpoint we set earlier.

Finally, you can use all Visual Studio debugging functions. For example, you can inspect a method in the 'Watch' window.

Additionally, you can perform the following actions:

Use the 'Step Over' function to move the execution to the next line.

Drag the execution line inside another statement.

Use the 'Step Into' function to step into a method and examine the execution of the code.

Summary¶

We hope the information in our article and video helped you debug cBots in Visual Studio. The debugging principles and operations reviewed here also apply to other professional IDEs.

For more information on cTrader Algo, see our documentation or post a question on our forum.