We seem to have found an issue with the ArcGISRuntime SDK for .net 100.8 release that's a regression over 100.7
Our application uses CompositeSymbols to represent our chart items, each containing 3 symbols: 1 PictureMarkerSymbol, 1 TextSymbol and 1 SimpleMarkerSymbol.
These composite symbols are displayed on a GraphicsOverlay with the rendering mode set to Dynamic.
We have implemented our own clustering algorithm that potentially removes existing graphics from the GraphicsOverlay and replaces them with new graphics when zooming in and out. The new graphics are displayed using various composite symbols to represent clusters in differing states of selection i.e Unselected, partially selected and fully selected.
The issue we are seeing is that when zooming in and out, the graphics overlay still displays random constituent parts of composite symbols for graphics that have been deleted.
For efficiency reasons, we actually only remove the graphics that are not being consumed by a new cluster, however testing has shown that even if we delete ALL graphics from the overlay (either iteratively or using the Clear method) before adding back the graphics relevant to the new zoom level, we're still left with these random remnants.
This only seems to be a problem when the GraphicsOverlay's RenderingMode is set to Dynamic and it also seems to be triggered by the combination of a PictureSymbol AND a TextSymbol. Just one graphic with this combination of symbols causes all other composite symbols (even cluster symbols that only contain SimpleMarkerSymbols and a TextSymbol) to randomly behave in the manner described.
It's worth noting that once a remnant is present, it never disappears (at any zoom level) and is not reported as being present in the GraphicOverlay's graphics collection.
For now we're working around this issue by using the Static rendering mode on the Graphics overlay, but that's obviously less visually appealing to our end users. Could you therefore please look into this to confirm the issue and let us know when it is likely to be fixed?
Attached are a couple of images demonstrating the problem.
The first map represents 6 of our chart items, (2 individual items and 4 inside a partially selected cluster)
The second is the same map zoomed in one level where the cluster of 4 items has split into 2 clusters of 2 items. Note the central blue and white circle with orange selection glow. This is a remnant of the composite symbol for the 4 item cluster shown at the previous zoom level, minus the TextSymbol showing the count which has clearly been deleted as expected. The graphic for this symbol has been deleted from the overlay and the overlays's graphic count is 4 despite there clearly being 5 composite symbols present.