Flutter 堆叠Stack高度自适应

在Stack中如果全部子元素都是Positioned元素， 那Stack必须有一个设置大小的父元素，否则会报错RenderStack object was given an infinite size during layout.

在Stack中将需要高度自适应的子元素设置成非Positioned元素， 通过padding来调整该元素的位置，实例如下

Stack(
  children: <Widget>[
    Positioned(
      top: setSize(18),
      right: setSize(6),
      child: Transform.rotate(
        angle: 3.14/4,
        child: Container(
          width: setSize(32),
          height: setSize(32),
          decoration: BoxDecoration(
            color: Color(0xff0CC6B6),
            borderRadius: BorderRadius.circular(setSize(4)),
          ),
        ),
      )
    ),
    Container(
      padding: EdgeInsets.only(right: setSize(16)),
      child: Container(
        padding: EdgeInsets.symmetric(horizontal: setSize(24), vertical: setSize(14)),
        constraints: BoxConstraints(
          maxWidth: setSize(470)
        ),
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(setSize(10)),
          color: Color(0xff0CC6B6)
        ),
        child: Text('撒大发撒大发阿斯顿发送到发送到发送地方', style: TextStyle(color: Color(0xffffffff), fontSize: setFont(28), fontWeight: FontWeight.w400, height: 40/28)),
      ),
    )
  ],
),