Donut charts act just like pie charts, except for an adjustable donut hole in the center of the chart. DonutChart is a subclass of PieChart, so all pie chart documentation also applies to donut chart.
Specifying Hole Radius
The hole radius of a donut chart can be specified by changing DonutChart.HoleRadiusPercentage. HoleRadiusPercentage determines what percentage of the DonutChart is consumed by the donut hole, from
0.0 (0%) to
A donut chart with a donut hole radius at 80%: