流式布局 - wrap

  Wrap({
    super.key,
    this.direction = Axis.horizontal, // 排列的方向，横向或纵向
    this.alignment = WrapAlignment.start, // 主轴方向，子项的对齐方式
    this.spacing = 0.0, // 主轴方向，子widget的间距
    this.runAlignment = WrapAlignment.start, // 侧轴的对齐方式
    this.runSpacing = 0.0, // 侧轴方向的间距
    this.crossAxisAlignment = WrapCrossAlignment.start, // 侧轴的对齐方式(每一行)
    this.textDirection,
    this.verticalDirection = VerticalDirection.down,
    this.clipBehavior = Clip.none,
    super.children,
  })