我想打电话
Scaffold.of(context).showSnackBar(SnackBar(
content: Text("Snack text"),));
在onPressed of floatingActionButton of scaffold.
我收到这个错误
I/flutter (18613): Scaffold.of() called with a context that does not contain a Scaffold. I/flutter (18613): No Scaffold ancestor could be found starting from the context that was passed to ....
当你在一个体内调用Scaffold.of(context)时,它指向一个解决方案.
解决方法
您应该将floatingActionButton小部件放在Builder小部件中.
以下代码应该有效：
以下代码应该有效：
@override
Widget build(BuildContext context) {
return new Scaffold(
floatingActionButton: new Builder(builder: (BuildContext context) {
return new FloatingActionButton(onPressed: () {
Scaffold
.of(context)
.showSnackBar(new SnackBar(content: new Text('Hello!')));
});
}),body: new Container(
padding: new EdgeInsets.all(32.0),child: new Column(
children: <Widget>[
new MySwitch(
value: _switchValue,onChanged: (bool value) {
if (value != _switchValue) {
setState(() {
_switchValue = value;
});
}
},)
],),);
