BorderStyle

/// 不显示
- none
/// 线
- solid

BorderSide

BorderSide({ this.color = const Color(0xFF000000), this.width = 1.0, this.style = BorderStyle.solid,})
static BorderSide merge(BorderSide a, BorderSide b)
BorderSide copyWith({Color color, double width, BorderStyle style, })
BorderSide scale(double t)
static bool canMerge(BorderSide a, BorderSide b)
static BorderSide lerp(BorderSide a, BorderSide b, double t)

• color: Color
• width: double
• style: BorderStyle

BoxDecoration(
       border: Border(
       top: BorderSide(width: 16.0, color: Colors.lightBlue.shade50),
       bottom: BorderSide(width: 16.0, color: Colors.lightBlue.shade900),
  )
)

static const

static const BorderSide none = BorderSide(width: 0.0, style: BorderStyle.none);