Core-plot Question : How to add a data Indicator

Answer 1

There is not really any direct way to do this type of interaction in Core Plot itself yet, though it is planned for future inclusion.

One way to do it would be to place your own UIView over the top of the graph, and use that to get mouse move events.

You could then have a few choices for showing the red line:

1) Add a second y axis, and position it according to the mouse events

2) Add a bar plot with exactly one bar, that extends over the whole vertical space

3) Add a scatter plot that has two points, one at the bottom, and one at the top.

These are all hacks, but they should all work.