How to have line rendered using OnBarUpdate calculated values

[Don22Trader1]

Hello,

I am having some trouble understanding how to correctly have a line rendered on the chart using values that are calculated on OnBarUpdate. Below I have attached a picture that shows two lines. The blue line is rendered in OnRender, and the purple line is a line drawn using DrawLine() in OnBarUpdate. The blue line needs to be rendered where the purple line is. I will provide a quick snippet of what I have written to make this happen.

if (State == State.SetDefaults)
{
Calculate = Calculate.OnBarClose;
DefaultBrush2 = System.Windows.Media.Brushes.DodgerBlue;
}

OnBarUpdate()
{
if (!TrendSwitchUp)
{
CreateUpLineOne = true;

//DrawLine
UpTrendLines = Draw.Line(this, "UpTrendLine" + CurrentBar.ToString(), false, TrendsLastBarsAgo, LastLow, 1, High[1], Brushes.DodgerBlue, DashStyleHelper.Solid, 4);
}
}

OnRender()
{
if (!IsInHitTest)
{
//UpLine Render Targets
SharpDX.Vector2 upStartPoint = new SharpDX.Vector2(ChartPanel.X, ChartPanel.Y);
SharpDX.Vector2 upEndPoint = new SharpDX.Vector2(ChartPanel.X + ChartPanel.W, ChartPanel.Y + ChartPanel.H);

//SharpDX Brush Resource
SharpDX.Direct2D1.Brush defaultBrush2Dx;

defaultBrush2Dx = DefaultBrush2.ToDxBrush(RenderTarget);

if (CreateUpLineOne)
{
//RenderLine
RenderTarget.DrawLine(upStartPoint, upEndPoint, defaultBrush2Dx, 2);​
}
defaultBrush2Dx.Dispose();
}
}

In the picture provided, the purple line is drawn after bar 1 has finished printing. On the DrawLine() method, "TrendsLastBarsAgo" = current session's first bar number (0) - Bars.BarsSinceNewTradingDay, "LastLow" = Low[TrendsLastBarsAgo], and the rest of the coordinates are pretty obvious.

The render targets for the blue line are just copied from the 'SampleCustomRender" indicator that Ninjatrader Provides, I did this to just get something on screen since it is my first time using SharpDx tools. It will be greatly appreciated if I can have a bit of guidance on how to get these render targets working correctly to mimic what the DrawLine() is doing.

[QuantKey_Bruce]

You need to use chartScale.GetYByValue() and chartControl.GetXByBarIndex() to get the coordinates to draw the line. Your line code does not look like it is related to the bars at all. In the help it describes how these functions work.

[NinjaTrader_Emily]

Hello Don22Trader1,

Thank you for your post.

There is an overview of SharpDX Vectors and Charting Coordinates in the help guide here:

https://ninjatrader.com/support/helpGuides/nt8/index.html?using_sharpdx_for_custom_chart_rendering.htm#SharpDXVectorsAndChartingCoordinates

For example, to get X and Y coordinates you could take advantage of the following methods:

• https://ninjatrader.com/support/help...bybarindex.htm
• https://ninjatrader.com/support/help...etybyvalue.htm

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