flutter - 方法 '[]'在null上被调用，但在inApp中有效
代码语言：javascript复制class DetailPage extends StatefulWidget {
final String text;
DetailPage ({Key key, @required this.text}) : super(key: key);
@override
_DetailPage createState() => _DetailPage();
}
class _DetailPage extends State<DetailPage> {
Map mapResponse;
Future fetchData() async {
Uri url = Uri.parse('');
Response<String> response = await Dio().request(url.toString(),
options: Options(
headers: {}));
if (response.statusCode == 200) {
setState(() {
mapResponse = json.decode(response.data);
});
}
}
@override
void initState() {
fetchData();
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
bottom: false,
child: Stack(children: <Widget>[
SingleChildScrollView(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(32.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
SizedBox(height: 300),
Text(
mapResponse['item']['name'],
style: TextStyle(
fontFamily: 'Avenir',
fontSize: 56,
color: Colors.blue,
fontWeight: FontWeight.w900,
),这就是我的json的样子
代码语言：javascript复制{
"status": true,
"item": {
"name": "Name here",
(moreJsonHere)最佳答案
这意味着检索数据需要很短的时间， 试试这个。数据为空时，它将在短时间内通过进度指示器
代码语言：javascript复制mapResponse !=null ? Text(
mapResponse['item']['name'],
style: TextStyle(
fontFamily: 'Avenir',
fontSize: 56,
color: Colors.blue,
fontWeight: FontWeight.w900,
):CircularProgressIndicator(),
