我目前正在嘗試決議這個 json 字串：
{"code":200,"status":"OK","results":{"datetime":[{"times":{"Imsak":"05:21","Sunrise":"06:43","Fajr":"05:31","Dhuhr":"12:32","Asr":"15:51","Sunset":"18:22","Maghrib":"18:32","Isha":"19:33","Midnight":"23:57"},"date":{"timestamp":1640736000,"gregorian":"2021-12-29","hijri":"1443-05-25"}}],"location":{"latitude":10.516667366027832,"longitude":7.433332920074462,"elevation":611.0,"city":"Kaduna","country":"Nigeria","country_code":"NG","timezone":"Africa/Lagos","local_offset":1.0},"settings":{"timeformat":"HH:mm","school":"Ithna Ashari","juristic":"Shafii","highlat":"None","fajr_angle":18.0,"isha_angle":18.0}}}
我創建了這個類：
class ParseJSON {
ParseJSON({
this.imsak,
this.sunrise,
this.fajr,
this.dhuhr,
this.asr,
this.sunset,
this.maghrib,
this.isha,
this.midnight,
});
String imsak;
String sunrise;
String fajr;
String dhuhr;
String asr;
String sunset;
String maghrib;
String isha;
String midnight;
factory ParseJSON.fromJson(Map<String, dynamic> json) => ParseJSON(
imsak: json["Imsak"],
sunrise: json["Sunrise"],
fajr: json["Fajr"],
dhuhr: json["Dhuhr"],
asr: json["Asr"],
sunset: json["Sunset"],
maghrib: json["Maghrib"],
isha: json["Isha"],
midnight: json["Midnight"],
);
Map<String, dynamic> toJson() => {
"Imsak": imsak,
"Sunrise": sunrise,
"Fajr": fajr,
"Dhuhr": dhuhr,
"Asr": asr,
"Sunset": sunset,
"Maghrib": maghrib,
"Isha": isha,
"Midnight": midnight,
};
}
我試圖訪問 json 的內容，因此：
Future<List<ParseJSON>> fetchJSON() async {
String jsonResponse = """
{"code":200,"status":"OK","results":{"datetime":[{"times":{"Imsak":"05:21","Sunrise":"06:43","Fajr":"05:31","Dhuhr":"12:32","Asr":"15:51","Sunset":"18:22","Maghrib":"18:32","Isha":"19:33","Midnight":"23:57"},"date":{"timestamp":1640736000,"gregorian":"2021-12-29","hijri":"1443-05-25"}}],"location":{"latitude":10.516667366027832,"longitude":7.433332920074462,"elevation":611.0,"city":"Kaduna","country":"Nigeria","country_code":"NG","timezone":"Africa/Lagos","local_offset":1.0},"settings":{"timeformat":"HH:mm","school":"Ithna Ashari","juristic":"Shafii","highlat":"None","fajr_angle":18.0,"isha_angle":18.0}}}
""";
ParseJSON welcomeFromJson(String str) => ParseJSON.fromJson(json.decode(str));
final welcome = welcomeFromJson(jsonResponse);
print("Printing contents from json string");
//print(jsonResponse);
print(welcome.maghrib);
print(welcome.fajr);
}
問題是，既print(welcome.maghrib)和print(welcome.fajr)回傳NULL。請問我做錯了什么？任何幫助，將不勝感激。謝謝
uj5u.com熱心網友回復：
您的模型類僅用于獲取“時間”物件，因此您需要在決議 Json 時進行以下更改，或者您需要更改您的模型類以決議 Response 中的每個欄位。
Future<List<ParseJSON>?> fetchJSON() async {
String jsonResponse = """
{"code":200,"status":"OK","results":{"datetime":[{"times":{"Imsak":"05:21","Sunrise":"06:43","Fajr":"05:31","Dhuhr":"12:32","Asr":"15:51","Sunset":"18:22","Maghrib":"18:32","Isha":"19:33","Midnight":"23:57"},"date":{"timestamp":1640736000,"gregorian":"2021-12-29","hijri":"1443-05-25"}}],"location":{"latitude":10.516667366027832,"longitude":7.433332920074462,"elevation":611.0,"city":"Kaduna","country":"Nigeria","country_code":"NG","timezone":"Africa/Lagos","local_offset":1.0},"settings":{"timeformat":"HH:mm","school":"Ithna Ashari","juristic":"Shafii","highlat":"None","fajr_angle":18.0,"isha_angle":18.0}}}
""";
var response = json.decode(jsonResponse);
ParseJSON welcome = ParseJSON.fromJson(response['results']['datetime'][0]['times']);
print("Printing contents from json string");
//print(jsonResponse);
print(welcome.maghrib);
print(welcome.fajr);
}
uj5u.com熱心網友回復：
您可以嘗試使用此代碼：
import 'dart:convert';
ParseJson parseJsonFromJson(String str) => ParseJson.fromJson(json.decode(str));
String parseJsonToJson(ParseJson data) => json.encode(data.toJson());
class ParseJson {
ParseJson({
this.code,
this.status,
this.results,
});
int code;
String status;
Results results;
factory ParseJson.fromJson(Map<String, dynamic> json) => ParseJson(
code: json["code"],
status: json["status"],
results: Results.fromJson(json["results"]),
);
Map<String, dynamic> toJson() => {
"code": code,
"status": status,
"results": results.toJson(),
};
}
class Results {
Results({
this.datetime,
this.location,
this.settings,
});
List<Datetime> datetime;
Location location;
Settings settings;
factory Results.fromJson(Map<String, dynamic> json) => Results(
datetime: List<Datetime>.from(json["datetime"].map((x) => Datetime.fromJson(x))),
location: Location.fromJson(json["location"]),
settings: Settings.fromJson(json["settings"]),
);
Map<String, dynamic> toJson() => {
"datetime": List<dynamic>.from(datetime.map((x) => x.toJson())),
"location": location.toJson(),
"settings": settings.toJson(),
};
}
class Datetime {
Datetime({
this.times,
this.date,
});
Times times;
Date date;
factory Datetime.fromJson(Map<String, dynamic> json) => Datetime(
times: Times.fromJson(json["times"]),
date: Date.fromJson(json["date"]),
);
Map<String, dynamic> toJson() => {
"times": times.toJson(),
"date": date.toJson(),
};
}
class Date {
Date({
this.timestamp,
this.gregorian,
this.hijri,
});
int timestamp;
DateTime gregorian;
DateTime hijri;
factory Date.fromJson(Map<String, dynamic> json) => Date(
timestamp: json["timestamp"],
gregorian: DateTime.parse(json["gregorian"]),
hijri: DateTime.parse(json["hijri"]),
);
Map<String, dynamic> toJson() => {
"timestamp": timestamp,
"gregorian": "${gregorian.year.toString().padLeft(4, '0')}-${gregorian.month.toString().padLeft(2, '0')}-${gregorian.day.toString().padLeft(2, '0')}",
"hijri": "${hijri.year.toString().padLeft(4, '0')}-${hijri.month.toString().padLeft(2, '0')}-${hijri.day.toString().padLeft(2, '0')}",
};
}
class Times {
Times({
this.imsak,
this.sunrise,
this.fajr,
this.dhuhr,
this.asr,
this.sunset,
this.maghrib,
this.isha,
this.midnight,
});
String imsak;
String sunrise;
String fajr;
String dhuhr;
String asr;
String sunset;
String maghrib;
String isha;
String midnight;
factory Times.fromJson(Map<String, dynamic> json) => Times(
imsak: json["Imsak"],
sunrise: json["Sunrise"],
fajr: json["Fajr"],
dhuhr: json["Dhuhr"],
asr: json["Asr"],
sunset: json["Sunset"],
maghrib: json["Maghrib"],
isha: json["Isha"],
midnight: json["Midnight"],
);
Map<String, dynamic> toJson() => {
"Imsak": imsak,
"Sunrise": sunrise,
"Fajr": fajr,
"Dhuhr": dhuhr,
"Asr": asr,
"Sunset": sunset,
"Maghrib": maghrib,
"Isha": isha,
"Midnight": midnight,
};
}
class Location {
Location({
this.latitude,
this.longitude,
this.elevation,
this.city,
this.country,
this.countryCode,
this.timezone,
this.localOffset,
});
double latitude;
double longitude;
int elevation;
String city;
String country;
String countryCode;
String timezone;
int localOffset;
factory Location.fromJson(Map<String, dynamic> json) => Location(
latitude: json["latitude"].toDouble(),
longitude: json["longitude"].toDouble(),
elevation: json["elevation"],
city: json["city"],
country: json["country"],
countryCode: json["country_code"],
timezone: json["timezone"],
localOffset: json["local_offset"],
);
Map<String, dynamic> toJson() => {
"latitude": latitude,
"longitude": longitude,
"elevation": elevation,
"city": city,
"country": country,
"country_code": countryCode,
"timezone": timezone,
"local_offset": localOffset,
};
}
class Settings {
Settings({
this.timeformat,
this.school,
this.juristic,
this.highlat,
this.fajrAngle,
this.ishaAngle,
});
String timeformat;
String school;
String juristic;
String highlat;
int fajrAngle;
int ishaAngle;
factory Settings.fromJson(Map<String, dynamic> json) => Settings(
timeformat: json["timeformat"],
school: json["school"],
juristic: json["juristic"],
highlat: json["highlat"],
fajrAngle: json["fajr_angle"],
ishaAngle: json["isha_angle"],
);
Map<String, dynamic> toJson() => {
"timeformat": timeformat,
"school": school,
"juristic": juristic,
"highlat": highlat,
"fajr_angle": fajrAngle,
"isha_angle": ishaAngle,
};
}
決議json時只需呼叫此行：
final parseJson = parseJsonFromJson(jsonString);
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