Question:
In an application, the data is being “drawn” by E3Chart, but when leaving the screen and returning to back to it, the chart is erased and it starts to redraw all data. Why does this happen? Can I keep the data?
Solution:
This behavior (drawing a new chart when returning to screen) is correct, because the pens were set up to work in real time only. Since the screen is redrawn every time it opens, the E3Chart has no way of knowing what the data previous to that time is.
To keep the data, that is, to draw again historic data, you must store them in a database and set the pens to Historic and Realtime. Thus, the E3Chart triggers a query in the database to recover the past values.
