IEX JSON API:
import 'package:http/http.dart' as http;
import 'dart:convert';
import '../models/stocks.dart';
Future<Map<String,dynamic>> getStocks() async {
// final String url =
'https://cloud.iexapis.com/stable/stock/market/batch?
symbols=aapl,fb&types=quote&token=Hidden';
// final client = new http.Client();
// final streamedRest = await client.send(
// http.Request('get', Uri.parse(url))
const url = 'https://cloud.iexapis.com/stable/stock/market/batch?s
ymbols=aapl,fb&types=quote&token=Hidden';
final response = await http.get(url);
final decodedResponse = json.decode(response.body).keys();
final data = Stocks.fromJson(decodedResponse);
//http.Response response = await http.get(Uri, headers: {"Accept":
"application/json"});
//print(jsonDecode(response.body).keys());
return jsonDecode(response.body).keys();
// return streamedRest.stream
// .transform(utf8.decoder)
// .transform(json.decoder)
// .expand((data) => (data as List<dynamic>))
// .map((data) => Stocks.fromJSON(data));
}
日志:
在以 Debug模式为x86构建的Android SDK上启动lib \ main.dart ...
正在初始化gradle ...
解决依赖性...
正在运行Gradle任务'assembleDebug'...
构建build \ app \ outputs \ apk \ debug \ app-debug.apk。
I / OpenGLRenderer(4854):初始化的EGL，版本1.4
D / OpenGLRenderer(4854):交换行为1
D /(4854):HostConnection::get()建立新的主机连接0xdc20bf00，tid 4881
D / EGL_emulation(4854):eglCreateContext:0xe3d47760:maj 2 min 0 rcv 2
D / EGL_emulation(4854):eglMakeCurrent:0xe3d47760:ver 2 0(tinfo 0xc6b24a30)
D /(4854):HostConnection::get()建立新的主机连接0xc6b386c0，TID 4874
D / EGL_emulation(4854):eglCreateContext:0xdc27d780:maj 2 min 0 rcv 2
D / EGL_emulation(4854):eglMakeCurrent:0xdc27d780:ver 2 0(tinfo 0xc6b24dc0)
正在将文件同步到针对x86构建的设备Android SDK ...
I / Choreographer(4854):跳过279帧!该应用程序可能在其主线程上做太多工作。
D / EGL_emulation(4854):eglMakeCurrent:0xe3d47760:ver 2 0(tinfo 0xc6b24a30)
I / OpenGLRenderer(4854):戴维!持续时间= 6180ms;标志= 1，IntendedVsync = 596431275408，Vsync = 601081275222，OldestInputEvent = 9223372036854775807，NewestInputEvent = 0，HandleInputStart = 601083214976，AnimationStart = 601083253387，PerformTraversalsStart = 601083255696，DrawStart = 601096302305，SyncQueued = 601333900000s，SwapStart = Draw335 = 694335，SyncStart = Draw335 = 694335 602308827762，FrameCompleted = 602612881859，DequeueBufferDuration = 66828000，QueueBufferDuration = 276000，
D / EGL_emulation(4854):eglMakeCurrent:0xdc27d780:ver 2 0(tinfo 0xc6b24dc0)
类
import 'dart:convert';
Stocks stocksFromJson(String str) => Stocks.fromJson(json.decode(str));
String stocksToJson(Stocks data) => json.encode(data.toJson());
class Stocks {
String symbol;
String companyName;
String primaryExchange;
String calculationPrice;
int open;
int openTime;
double close;
int closeTime;
double high;
double low;
double latestPrice;
String latestSource;
String latestTime;
int latestUpdate;
int latestVolume;
dynamic iexRealtimePrice;
dynamic iexRealtimeSize;
dynamic iexLastUpdated;
double delayedPrice;
int delayedPriceTime;
double extendedPrice;
double extendedChange;
double extendedChangePercent;
int extendedPriceTime;
double previousClose;
int previousVolume;
int change;
double changePercent;
int volume;
dynamic iexMarketPercent;
dynamic iexVolume;
int avgTotalVolume;
dynamic iexBidPrice;
dynamic iexBidSize;
dynamic iexAskPrice;
dynamic iexAskSize;
int marketCap;
double peRatio;
double week52High;
int week52Low;
double ytdChange;
int lastTradeTime;
bool isUsMarketOpen;
Stocks({
this.symbol,
this.companyName,
this.primaryExchange,
this.calculationPrice,
this.open,
this.openTime,
this.close,
this.closeTime,
this.high,
this.low,
this.latestPrice,
this.latestSource,
this.latestTime,
this.latestUpdate,
this.latestVolume,
this.iexRealtimePrice,
this.iexRealtimeSize,
this.iexLastUpdated,
this.delayedPrice,
this.delayedPriceTime,
this.extendedPrice,
this.extendedChange,
this.extendedChangePercent,
this.extendedPriceTime,
this.previousClose,
this.previousVolume,
this.change,
this.changePercent,
this.volume,
this.iexMarketPercent,
this.iexVolume,
this.avgTotalVolume,
this.iexBidPrice,
this.iexBidSize,
this.iexAskPrice,
this.iexAskSize,
this.marketCap,
this.peRatio,
this.week52High,
this.week52Low,
this.ytdChange,
this.lastTradeTime,
this.isUsMarketOpen,
});
factory Stocks.fromJson(Map<String, dynamic> json) => Stocks(
symbol: json["symbol"],
companyName: json["companyName"],
primaryExchange: json["primaryExchange"],
calculationPrice: json["calculationPrice"],
open: json["open"],
openTime: json["openTime"],
close: json["close"].toDouble(),
closeTime: json["closeTime"],
high: json["high"].toDouble(),
low: json["low"].toDouble(),
latestPrice: json["latestPrice"].toDouble(),
latestSource: json["latestSource"],
latestTime: json["latestTime"],
latestUpdate: json["latestUpdate"],
latestVolume: json["latestVolume"],
iexRealtimePrice: json["iexRealtimePrice"],
iexRealtimeSize: json["iexRealtimeSize"],
iexLastUpdated: json["iexLastUpdated"],
delayedPrice: json["delayedPrice"].toDouble(),
delayedPriceTime: json["delayedPriceTime"],
extendedPrice: json["extendedPrice"].toDouble(),
extendedChange: json["extendedChange"].toDouble(),
extendedChangePercent: json["extendedChangePercent"].toDouble(),
extendedPriceTime: json["extendedPriceTime"],
previousClose: json["previousClose"].toDouble(),
previousVolume: json["previousVolume"],
change: json["change"],
changePercent: json["changePercent"].toDouble(),
volume: json["volume"],
iexMarketPercent: json["iexMarketPercent"],
iexVolume: json["iexVolume"],
avgTotalVolume: json["avgTotalVolume"],
iexBidPrice: json["iexBidPrice"],
iexBidSize: json["iexBidSize"],
iexAskPrice: json["iexAskPrice"],
iexAskSize: json["iexAskSize"],
marketCap: json["marketCap"],
peRatio: json["peRatio"].toDouble(),
week52High: json["week52High"].toDouble(),
week52Low: json["week52Low"],
ytdChange: json["ytdChange"].toDouble(),
lastTradeTime: json["lastTradeTime"],
isUsMarketOpen: json["isUSMarketOpen"],
);
Map<String, dynamic> toJson() => {
"symbol": symbol,
"companyName": companyName,
"primaryExchange": primaryExchange,
"calculationPrice": calculationPrice,
"open": open,
"openTime": openTime,
"close": close,
"closeTime": closeTime,
"high": high,
"low": low,
"latestPrice": latestPrice,
"latestSource": latestSource,
"latestTime": latestTime,
"latestUpdate": latestUpdate,
"latestVolume": latestVolume,
"iexRealtimePrice": iexRealtimePrice,
"iexRealtimeSize": iexRealtimeSize,
"iexLastUpdated": iexLastUpdated,
"delayedPrice": delayedPrice,
"delayedPriceTime": delayedPriceTime,
"extendedPrice": extendedPrice,
"extendedChange": extendedChange,
"extendedChangePercent": extendedChangePercent,
"extendedPriceTime": extendedPriceTime,
"previousClose": previousClose,
"previousVolume": previousVolume,
"change": change,
"changePercent": changePercent,
"volume": volume,
"iexMarketPercent": iexMarketPercent,
"iexVolume": iexVolume,
"avgTotalVolume": avgTotalVolume,
"iexBidPrice": iexBidPrice,
"iexBidSize": iexBidSize,
"iexAskPrice": iexAskPrice,
"iexAskSize": iexAskSize,
"marketCap": marketCap,
"peRatio": peRatio,
"week52High": week52High,
"week52Low": week52Low,
"ytdChange": ytdChange,
"lastTradeTime": lastTradeTime,
"isUSMarketOpen": isUsMarketOpen,
};
}
没有错误生成，但也没有结果。
最佳答案
看来问题是.expand((data) => (data as List))，看来您的API返回的是JSON对象( map )而不是JSON数组(列表)
我还想出了另一个细节，“AAPL”是JSON对象上的键，该值是另一个JSON对象，如果要将其值映射到Class，则可以使用扩展获取“AAPL”的值并传递它到你的工厂fromJSON
另一个重要的事情是，确保要尝试映射到Class的键在传递的JSON对象中存在。
为了避免动态键(可能没有出现的键)出现问题，您可以使用Null感知运算符
一个使事情变得简单的建议，也许是不要使用Streams，您可以仅使用Future来重构代码以实现异步
const url = 'http://example.com/';
final response = await http.get(url);
final decodedResponse = json.decode(response);
final yourObject = Class.fromJSON(decodedResponse);
最后但并非最不重要的一点，我强烈建议您看一下: