Thanks for your help. This method solve the problem. But it causes other problems too.
The bar "gapPercent" and "widthPercent" become useless. Sometimes bar will overlap .
The "scaleX.LabelStyle.ContentAlignment" and "LabelFitModes" can not affect these custom labels.
These custom labels set to "stagger2, autoscale" fitmode. How can I change their fitmode?
By the way, my nevron version is 9.1.13.12.
Thanks,
-Jacky