是一个效果控件 ，点击有泼墨的水波的效果 ，长和Material+颜色透明一起使用
example
Material(
// 透明
color: Colors.transparent,
child: InkWell(
splashColor: Colors.white.withOpacity(0.1),
highlightColor: Colors.transparent,
borderRadius: BorderRadius.circular(8),
onTap: onTap,
child: Center(
child: Container(
width: 48,
height: 48,
alignment: Alignment.center,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(60),
color: Colors.amber,
),
child: Text(
title,
style: TextStyle(
fontSize: 24,
color: Colors.white,
fontWeight: FontWeight.bold,
),
),
),
),
),
)
