Flutter基础widgets教程-FractionallySizedBox篇

1 FractionallySizedBox

一个widget，它把它的子项放在可用空间的一小部分

FractionallySizedBox({
    Key key,
    this.alignment = Alignment.center,
    this.widthFactor,
    this.heightFactor,
    Widget child,
})

alignment:Alignment.topLeft,

3.1.1 顶部左边

alignment:Alignment.topLeft,

3.1.2 顶部中间

alignment:Alignment.topCenter,

3.1.3 顶部右边

alignment:Alignment.topRight,

3.1.4 中部左边

alignment:Alignment.centerLeft,

3.1.5 中部中间

alignment:Alignment.center,

3.1.6 中部右边

alignment:Alignment.centerRight,

3.1.7 底部左边

alignment:Alignment.bottomLeft,

3.1.8 底部中间

alignment:Alignment.bottomCenter,

3.1.9 底部右边

alignment:Alignment.bottomRight,

widthFactor: 0.5,

heightFactor: 0.5,

child: Text('你好 Flutter'),