FractionallySizedBox
一个将其子部件大小调整为总可用空间一定比例的部件。有关布局算法的更多细节,请参见 RenderFractionallySizedOverflowBox
示例
SizedBox.expand(
child: FractionallySizedBox(
widthFactor: 0.5,
heightFactor: 0.5,
alignment: Alignment.center,
child: DecoratedBox(
decoration: BoxDecoration(border: Border.all(color: Colors.blue, width: 4)),
),
),
)

这个例子展示了根据Factor系数将子组件的宽高都设置为父组件的50%,根据alignment设置排列子组件在父组件中间。
构造函数
FractionallySizedBox.new({
Key? key,
AlignmentGeometry alignment = Alignment.center,
double? widthFactor,
double? heightFactor,
Widget? child
})
属性
| 属性名 | 属性类型 | 说明 |
|---|---|---|
| alignment | AlignmentGeometry | 对齐方式 |
| child | Widget? | 子组件 |
| heightFactor | double? | 高度系数 |
| widthFactor | double? | 宽度系数 |