Offstage(
  offstage:false,
  child: Container(
    width: 200,
    height: 200,
    color: Colors.red,
  ),
),

Visibility(
  visible:_offstage,
  replacement:Text('data'),
  maintainState:true,
  child: Container(
    width: 200,
    height: 200,
    color: Colors.yellow,
  ),
),

四种方式控制显隐

import 'package:flutter/material.dart';
 
class Test extends StatelessWidget {
  bool isShow=false;
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Row(
        children: <Widget>[
          Visibility(child: null,visible:false,),
          Offstage(offstage:false,child:null),
          Opacity(opacity: 1,child:null),
          isShow?Text("显示"):SizedBox.shrink()
        ],
      ),
    );
  }
}