If data is not set (e.g. public var noDataText = "No chart data available.")

[sabiland]

If data is not set (e.g. public var noDataText = "No chart data available."), graph is not re-drawn after rotating device. That means "No chart data available." text is stretched /squeezed.

[liuxuan30]

in controller code, use following (though deprecated in iOS 8.0)

-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    [_chartView setNeedsDisplay];
}

will redraw the chart can solve the issue.
ChartDemo does not provide this support yet.

[danielgindi]

Does this mean that the UIView does not setNeedsDisplay when changing frame? Looks like a given that the OS should do that