Draw only once

[Tzachi]

Hi all,

I have this simple kind of "if":

protected override void OnBarUpdate()
{
// Use this method for calculating your indicator values. Assign a value to each
// plot below by replacing 'Close[0]' with your own formula.
Plot0.Set(Close[0]);

if (CurrentBar < 26)return;
if (CrossAbove(CCI(14), 5,5)&&XYZ[0]>XYZ[1] )
{
///Do something
DrawArrowUp("Dot"+ CurrentBar , false, 1,High[0]- 8*TickSize, Color.Gold);
}

The problem is that it will draw the arrow below EVERY bar that match the above condition when all what I want ids to draw it only one (first time conditions met)

Help to fix the code will be greatly appreciated.

[NinjaTrader_Jim]

Hello Tzachi,

Thanks for your inquiry.

You can accomplish such a task by creating a doOnce bool and including that with your if statement.

I've attached a hypothetical example below:

private bool doOnce = true;

protected override void OnBarUpdate()
{
	if(VariableA > VariableB && doOnce == true)
	{
		// Do something
		doOnce = false; // Set to false so we don't do it again.
	}
	
	if(SomeConditionToReset)
	{
		doOnce = true; // Reset the doOnce bool when we want to allow it to trigger again
	}
}

Our publicly available Basic Programming Syntax documentation should provide enough reference for this task: https://ninjatrader.com/support/help...sic_syntax.htm

Please let me know if you have any questions.

[Tzachi]

Many thanks for your quick reply.

When I added "private doOnce = true;"

and the condition into the If... I get an error below:

Invalid token '=' in class, struct, or interface member declaration

[NinjaTrader_Jim]

Oops!

I forgot to include the type with the declaration.

Should be: private bool doOnce = true;

[Tzachi]

Thank you.

Now no error but when have:

if (XYZ [0] > XYZ[1] && doOnce == true)
{

DrawArrowUp("Dot"+ CurrentBar , false, 1,High[0]- 8*TickSize, Color.Gold);
doOnce = false;
}
I get no arrows at all.

[NinjaTrader_Jim]

Hello Tzachi,

Please use Print() statements to monitor your logic as it executes. Likely, the arrow drew on the first time the condition became true, and since the bool is no longer set to true, the arrow never draws again.

You will want to create Print statements that tell you the values of the variables you use in your if statement before the if statement is reached so you can see how it is evaluated.

I've included a forum post for more information on debugging your code:

Debugging - https://ninjatrader.com/support/foru...ead.php?t=3418

Please let us know if we can be of further assistance.

[Tzachi]

Via Print method I found out that it did print the arrow up one time, (like 20 days ago), the first time when conditions agreed upon as it should do - but never again.

Any Idea why it was not resetting to look for the conditions later on?

[NinjaTrader_Jim]

You need to create a condition that resets the doOnce bool variable back to true.

if(SomeConditionToReset)
{
	doOnce = true; // Reset the doOnce bool when we want to allow it to trigger again
}

[Tzachi]

BEAUTIFUL

Works as I wished for.

Many thanks.