苏州学习网站建设,制作网站建设,网站维护 案例,网站开发与设计实训心得1、Align介绍
Align的作为一个参数#xff0c;设置子child的对齐方式#xff0c;比如居中#xff0c;左上#xff0c;右下等多个对齐方向 2、部分源码和功能 const Align({Key key,this.alignment Alignment.center,this.widthFactor,this.heightFactor,Widget child,}) …1、Align介绍
Align的作为一个参数设置子child的对齐方式比如居中左上右下等多个对齐方向 2、部分源码和功能 const Align({Key key,this.alignment Alignment.center,this.widthFactor,this.heightFactor,Widget child,}) : assert(alignment ! null),assert(widthFactor null || widthFactor 0.0),assert(heightFactor null || heightFactor 0.0),super(key: key, child: child); /// The top left corner.static const Alignment topLeft Alignment(-1.0, -1.0);/// The center point along the top edge.static const Alignment topCenter Alignment(0.0, -1.0);/// The top right corner.static const Alignment topRight Alignment(1.0, -1.0);/// The center point along the left edge.static const Alignment centerLeft Alignment(-1.0, 0.0);/// The center point, both horizontally and vertically.static const Alignment center Alignment(0.0, 0.0);/// The center point along the right edge.static const Alignment centerRight Alignment(1.0, 0.0);/// The bottom left corner.static const Alignment bottomLeft Alignment(-1.0, 1.0);/// The center point along the bottom edge.static const Alignment bottomCenter Alignment(0.0, 1.0);/// The bottom right corner.static const Alignment bottomRight Alignment(1.0, 1.0); 我们知道最左上角的坐标是Alignment(-1.0, -1.0),中心坐标是Alignment(0.0, 0.0);然后最右下角坐标是Alignment(1.0, 1.0);
FractionalOffset对其封装了大小范围是(0~1),FractionalOffset(0, 0)对于左上角FractionalOffset(1, 1)对于右下角FractionalOffset(0.5, 0.5)对于中间坐标
FractionalOffset(0.5, 0.5) Alignment(0.0,0.0) Alignment.center 3、测试代码
测试1 overrideWidget build(BuildContext context) {return MaterialApp(title: open url,home: Scaffold(appBar: AppBar(// Here we take the value from the MyHomePage object that was created by// the App.build method, and use it to set our appbar title.title: Text(hello flutter),),body: Align(alignment: FractionalOffset(1, 0),child: Container(color: Colors.red,width: 100,height: 100,),),),);}
测试2 overrideWidget build(BuildContext context) {return MaterialApp(title: open url,home: Scaffold(appBar: AppBar(// Here we take the value from the MyHomePage object that was created by// the App.build method, and use it to set our appbar title.title: Text(hello flutter),),body: Align(alignment: FractionalOffset(0.5, 0),child: Text(chenyu),),),);}
} 4、运行效果
测试1结果 项目结构如下 测试2结果
