Multiple TouchEffects cause crash on iOS

[Hackmodford]

I've noticed a crash in my app if there are multiple graphs.

For example I have two pages with graphs.

If I navigate A -> B -> A then try to touch Graph A, the app crashes in the PlotViewBase.Events.cs file.

This is do to previousTouchPoints being nil. It seems that the TouchEffect is associated with the wrong view? Not sure. Or they're all sending reports to each other.

[Hackmodford]

My current solution was to carefully set the InputTransparency property on the graphs to true if they are not visible, but as you can imagine that is a bit of a pain to manage.

This was the original reason for my earlier commit.

[janusw]

Is it possible to reproduce this problem with the sample app? Could you please provide the full error message / exception ?

[Hackmodford]

I'm working on generating a sample project.

I believe I have triggered the issue by having two graphs and starting a drag on one graph and sliding my finger over to the other graph.

[Hackmodford]

Here is my minimal example project.
I believe this is the key line causing me issues.

If you try dragging the circle on iOS it will crash.

https://github.com/Hackmodford/oxyplot-maui-crash1

The key seems to be with settings the opacity of the plot.
It may also crash if you have the graphs side by side and try starting in one plot and dragging to the other.

In any case the example in the project is what is causing me headaches in my current app.

[jaison-t-john]

@Hackmodford, Can I know if pinch to zoom is working for you in iOS?

[RobertStefancic]

@Hackmodford could you please test the latest version 1.0.1 that includes the fix from #10
I took a glance on your issue and this fix has a good probability to solve it.