Flutter基础widgets教程-OverflowBox篇

OverflowBox({
    Key key,
    this.alignment = Alignment.center,
    this.minWidth,
    this.maxWidth,
    this.minHeight,
    this.maxHeight,
    Widget child,
})

alignment:Alignment.center,

alignment:Alignment.topLeft,

alignment:Alignment.topCenter,

alignment:Alignment.topRight,

alignment:Alignment.centerLeft,

alignment:Alignment.center,

alignment:Alignment.centerRight,

alignment:Alignment.bottomLeft,

alignment:Alignment.bottomCenter,

alignment:Alignment.bottomRight,

minWidth: 200.0,

maxWidth: 200.0,

minHeight: 200.0,

maxHeight: 200.0,

child: Text('你好 Flutter'),

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_markdown/flutter_markdown.dart';
// 字体适配
import '../../utils/app_size.dart';

class ListOverflowBox extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return DefaultTabController(
      length: 2,
      child: Scaffold(
        appBar: AppBar(
          title: Text('OverflowBox'),
          backgroundColor: Color(0xFFfafcff),
          bottom: TabBar(labelColor: Color(0xff030303), tabs: [
            Tab(
              text: "效果",
            ),
            Tab(
              text: "属性",
            )
          ]),
        ),
        body: TabBarView(children: [
          Container(
              decoration: new BoxDecoration(
                color: new Color(0xffffffff),
                borderRadius: new BorderRadius.circular((AppSize.width(20))),
              ),
              child: ShowEffect()),
          Container(
              decoration: new BoxDecoration(
                color: new Color(0xffffffff),
                borderRadius: new BorderRadius.circular((AppSize.width(20))),
              ),
              child: ShowAttribute()),
        ]),
      ),
    );
  }
}

// 效果
class ShowEffect extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text("WidgetsApp Demo"),
        ),
        body: Container(
          //1 注意：父容器的宽高是200 减去pading后是180
          padding: EdgeInsets.all(10),
          color: Colors.green,
          width: 200,
          height: 200,
          child: new OverflowBox(
            maxHeight: 400, //2 不能小于父容器的高度180
            child: new Container(
              color: Colors.deepOrange,
              width: 200,
              height: 600,
            ),
          ),
        ),
      ),
    );
  }
}

// 属性
class ShowAttribute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: FutureBuilder(
        future: rootBundle.loadString('lib/markdown/overflowBox.md'),
        builder: (BuildContext context, AsyncSnapshot snapshot) {
          if (snapshot.hasData) {
            return Markdown(
              data: snapshot.data,
              selectable: true,
            );
          } else {
            return Center(
              child: Text("加载中..."),
            );
          }
        },
      ),
    );
  }
}