NC Block Marker Description
NC Block Marker is an order block marker for NinjaTrader 8, and it comes with the full C# source code. Automatic indicators often fill the chart with levels that are outdated or not relevant. Sometimes you just want to mark the few blocks you believe in and let the chart keep track of them: you pick the blocks, it watches them. One honest limitation: blocks are kept in memory only, so they're gone when you reload the indicator or the chart.
How a block is marked. The indicator adds three buttons to the chart toolbar: MARK LONG, MARK SHORT and CLEAR. Press MARK LONG (it turns orange-red while armed), then click a bar, and that bar becomes a long block; MARK SHORT does the same for a short block. Each press marks one block, and pressing the button again cancels it. Sizing Type sets the block's height: UseBarBody (the default) uses the candle body, UseHighLow the whole bar from high to low. A long block stays active until a bar closes below its bottom, and a short block until a bar closes above its top. If you mark an older bar, the indicator checks every bar since then right away, so the block shows its real state.
What you see. Each block is a shaded zone that starts at the marked bar and extends right with every new bar while it holds. Long blocks are green (Up Block Color) and short blocks red (Down Block Color). When a bar closes through a block, it turns gray (Invalid Up Block Color or Invalid Down Block Color) and stops extending. Block Opacity (0.5 by default) sets how see-through the zones are. CLEAR removes all blocks at once. Blocks are checked when each bar closes.
How to use it. Mark the blocks you would trade from before your session starts, and let the indicator tell you which ones still hold. Use UseBarBody for tighter zones, and UseHighLow when you want the wicks included.
Make it yours. Like all my frameworks, it comes with a code review video that walks through the code and how it works with the chart UI. Use it as is, learn from the code, or change it yourself or with AI like Claude. You could save the blocks so they survive a reload, add an alert when price comes back into an active block, or let a click remove a single block. The code is also a handy example of working with the NinjaTrader UI (toolbar buttons, tab switching, mouse clicks on bars), kept apart from the block logic and drawing, so it's an easy base to build on. Have some good trades!
