Json 类别';列表<;用户>';没有实例getter';长度';。接收方:实例(长度:5)的'_可增长列表';试着打电话:Lengh
你好,我收到这个错误Json 类别';列表<;用户>';没有实例getter';长度';。接收方:实例(长度:5)的'_可增长列表';试着打电话:Lengh,json,flutter,Json,Flutter,你好,我收到这个错误 Class 'List<User>' has no instance getter 'lenght'. Receiver: Instance(length:5) of '_GrowableList' Tried calling: lenght Future getData()异步{ var data=wait http.get('http://maen.mis-web.com/generated.json'); var jsonData=json.decode
Class 'List<User>' has no instance getter 'lenght'.
Receiver: Instance(length:5) of '_GrowableList'
Tried calling: lenght
Future getData()异步{
var data=wait http.get('http://maen.mis-web.com/generated.json');
var jsonData=json.decode(data.body);
列出用户=[];
用于(jsonData中的变量u){
用户=用户(u[“索引”]、u[“名称”]、u[“dep”]、u[“pic”]);
用户。添加(用户);
}
打印(用户.长度);
返回用户;
}
void initState(){
getData();
super.initState();
}
Widget futureList(){
回归未来建设者(
future:getData(),
生成器:(BuildContext上下文,异步快照){
打印(快照数据);
如果(snapshot.data==null){
返回颜色加载程序2(
颜色1:Colors.redAccent,
颜色2:颜色,绿色,
颜色3:颜色。琥珀色,
);
}否则{
返回ListView.builder(
itemCount:snapshot.data.lenght,
itemBuilder:(构建上下文,int索引){
返回列表块(
领先:CircleAvatar(
背景图片:NetworkImage(
snapshot.data[index].pic
),
),
标题:文本(快照.数据[索引].名称),
字幕:文本(快照.data[index].dep),
);
},
);
}
},
);
}
应该是
itemCount: snapshot.data.length
您在
snapshot.data.lenght
处拼写错误length
。请注意,在itemCountsnapshot.data.lenght
中,请正确写入length
Future<List<User>> getData() async{
var data = await http.get('http://maen.mis-web.com/generated.json');
var jsonData = json.decode(data.body);
List<User> users = [];
for(var u in jsonData){
User user = User(u["index"], u["name"], u["dep"], u["pic"]);
users.add(user);
}
print(users.length);
return users;
}
void initState(){
getData();
super.initState();
}
Widget futureList(){
return FutureBuilder(
future: getData(),
builder: (BuildContext context, AsyncSnapshot snapshot){
print(snapshot.data);
if (snapshot.data == null){
return ColorLoader2(
color1: Colors.redAccent,
color2: Colors.green,
color3: Colors.amber,
);
} else {
return ListView.builder(
itemCount: snapshot.data.lenght,
itemBuilder: (BuildContext context, int index){
return ListTile(
leading: CircleAvatar(
backgroundImage: NetworkImage(
snapshot.data[index].pic
),
),
title: Text(snapshot.data[index].name),
subtitle: Text(snapshot.data[index].dep),
);
},
);
}
},
);
}
itemCount: snapshot.data.lenght
itemCount: snapshot.data.length