Modify the postion of a trend line drawn with OnRender

[Shai Samuel]

Hi,

Using OnRender, I need to draw a trend line and extend its position on each bar. Is there a way to change points of a line, or I would need to remove the old line and create a new one? Any example?

[NinjaTrader_ChelseaB]

Hello Shai Samuel,

That's not how RenderTarget.DrawLine() works.

https://ninjatrader.com/support/helpGuides/nt8/sharpdx_direct2d1_rendertarget_drawline.htm

The line is drawn on each render pass. If you change the Vector2 points supplied it will draw to those new points.

If you don't want something drawn, there is remove method. Just don't call the RenderTarget.DrawLine() and object won't be rendered.

[Shai Samuel]

Just to make sure I understand, OnRender is called within each change (price move...), and of course each screen scrolls or changes proportions?

[NinjaTrader_ChelseaB]

Hello Shai Samuel,

OnRender() runs for every render pass. This is used for custom rendering. (Not like OnBarUpdate() which updates for every price change, tick received, or bar close, where Draw methods like Draw.Line() would be called)