Get chart image without rendering chart

[robert-cronin]

I am trying to export a line chart image and save it in the UIImage however I also need to be able to do it without rendering it in any UIView on any View Controller.

But when I do, the image turns out to be just a blank white image. I can get an image if I save the image in viewDidAppear after the view has been loaded.

Is there any way to do this without adding the chart view to the view controller?

[liuxuan30]

ask on stack overflow, this is an UIView question.

But this library provides

    /// - returns: The bitmap that represents the chart.
    @objc open func getChartImage(transparent: Bool) -> NSUIImage?