You indicated that the Product of this thread is Chart for Xamarin Cross-Platform, but it seems that you are asking about the Gauge so I changed the Product to Gauges for Xamarin Cross-Platform.
At the moment the gauge lacks ZIndex functionality and the default order of drawing is as follows:
1. Axis elements are drawn first
2. Ranges are drawn on top
3. Indicators are drawn on top
Note that the indicators are drawn in the order they appear in the Indicators collection.
From the above explanation one expects to see that the needle should always be drawn on top of the ranges. But because this does not happen in your case, I suspect that the blue-green-red ring is not ranges, it is three bar indicators. Perhaps the bar indicators are added after the needle indicator and this is why it is below the bars. You need to simply add the needle last, after the bars.
Because you are using the the blue-green-red ring as ranges (not to show a particular value, but give meaningful context of the needle value) I suggest that you don't use bar indicators - use ranges
I hope I was able to address your question accordingly. Let us know if you need more information.
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