DataVisualization.Charting.Chart PostPaint事件过早触发

Question

I have a complex chart that I'm drawing and the PostPaint event for System.Windows.Forms.DataVisualization.Charting.Chart seems to be firing prematurely. There is no chart on the screen yet.

Does anyone have a better understanding of the behavior of the PostPaint event with large charts? Is there a better event to listen to? Recommended strategies?

I'm not sure posting code would provide any benefit.

Answer 1

ORIGINAL POST: So it turns out the answer to this (for me anyway), is to create another thread (I'm doing it with a Task) off of the event. This thread's job is to continually compare the region with an empty image and when it is no longer empty, grab the image and save it in the database. Because it's a thread, this frees up the chart to eventually render itself.

FINAL POST: In the end, I had to put a lock inside the PostPaint event (it was firing multiple times as TaW indicated it would) and make sure the code inside would only execute a single time (I have a Draw button so these controls get reset every time it's clicked). Additionally, it was necessary for me to create a task to actually do the work of capturing the image and storing it in the database. If I didn't do this, I would get a blank image every time. I did not actually have to check point count or sample the image to see if it was blank.

Locking down the event and creating the task inside the event is what made the difference.