enum PlaySpeed { pointTwoFive, pointFive, pointSevenFive, one, onePointTwoFive, onePointFive, onePointSevenFive, two, } extension PlaySpeedExtension on PlaySpeed { static final List _descList = [ '0.25', '0.5', '0.75', '正常', '1.25', '1.5', '1.75', '2.0', ]; get description => _descList[index]; static final List _valueList = [ 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, ]; get value => _valueList[index]; get defaultValue => _valueList[3]; }