How to change pie graph legands value


this is now my pie chart looks like…i want to change legand values with names…Any method?
i have one more doubts
1 . i am not able to set chart at top ,ie when we set margin top =“0” it is not such near to actionbar…there is same space …
In my screenshot Daily usage is Set after action bar but there is a gap .how to clear that ?
2 . how to set trackball in pie chart ? on bar chart it is posssible.
3 . how to set different style for different orientation such as portarit and landscape ?
4 . How to make zoom in pie chart…zoom in barchart is okey

  1. You can set the legend names with the legendLabel property on your chart:PieSeries element.
  2. I would need to view your layout code to see what is causing the extra spacing. Any other UI elements or layouts in there?
  3. Here are the docs on implementing a trackball.
  4. You can have separate views based on orientation. Check these docs.
  5. And here are the docs for pan and zoom.