Error: "Brush series exceeds the maximum number (65535) of unique brushes"

[Nagash]

Hi,

I modified an MACD indicator to paint the panel background in different colors based on conditions. I actually use 2 colors (buy / sell) with different opacities based on a "signal strength".

When back-testing a strategy using this indicator, I get the following error, if used on a small frequency chart (ex: 30 seconds) on a 2 weeks period:

"Brush series exceeds the maximum number (65535) of unique brushes. Please adjust code to use fewer brushes."

The visual consequence is that after a certain amount of time, the back brush color doesn't change anymore, in the Strategy Analyzer chart.

The way I change the BackBrush in the OnBarUpdate is the following:

Brush b = BuyBackgroundBrush.Clone();
b.Opacity= buySignalStrengh * OpacityFactor / 100.0;                     
BackBrush = b;
BackBrush.Freeze(); // I didn't have the Freeze until now, but it doesn't change anything.

Opacity Factor = 10 by default.
BuySignalStrength = 1 to 4, depending on conditions.

My BuyBackgroundBrush is a property defined as

[XmlIgnore]
[Display(ResourceType = typeof(Custom.Resource), Name = "Buy Signal Background Color", Order=3, GroupName = "Signal Parameters")]
public Brush BuyBackgroundBrush
{get; set;}

Not sure what I am missing to avoid having so many brushes used by the indicator.

Thanks for your help.

[NinjaTrader_Jesse]

Hello Nagash,

Thank you for the post.

This is a normal message if you use too many brushes, the solution would be to just use less brushes.

For the backtest you could add a user input to disable drawing to avoid the messages. Another alternative is to use OnRender to paint rather than using the individual brush per bar that BarBrush will create. A bool series could be used to store a true/false per bar to know if it should be marked or not and then OnRender could use that data to paint just the current visible bars.

I look forward to being of further assistance.

[Matheusfx]

I'd suggest creating all the possible Brushes during initialization, and storing them in a List. During the indicator execution you can then select the appropriate Brush according to your indicator logic.