圆形：
ClipOval(
child: FadeInImage.assetNetwork(
placeholder: "images/limited-time.png",
image: "",
fit: BoxFit.cover,
width: sWidth(75),
height: sWidth(75),
fadeInDuration: new Duration(milliseconds: 1),
fadeOutDuration: new Duration(milliseconds: 1),
//width: ScreenUtil().setWidth(90)
),
),
可以设置圆角：
new CircleAvatar(
backgroundImage: AssetImage('assets/home_icon_default_business_avatar.png'),
radius: 15.0,
// child: , //增加文字等
),
