主体上带有 Json 的 HTTP POST 方法 - Flutter/Dart

Question

带有 Json 的 HTTP POST 方法 - Flutter/Dart：

 Future<List<dynamic>> requestMethodtwo() async {
    var url = "";
    var body = json.encode({"finYr": "6", "UserID": "1"});
    setState(() {
      isLoading = true;
    });
    Map<String, String> headers = {
      'Content-type': 'application/json',
      'Accept': 'application/json',
    };
    final response =
    await http.post(url, body: body, headers: headers);
    final responseJson = json.decode(response.body);
    final items = json.decode(response.body).cast<Map<String, dynamic>>();
    List<dynamic> listOfString = items.map((json) {
      return json['rows'];
    }).toList();
    print(listOf[enter image description here][1]String);
    print(response.statusCode);
    if (response.statusCode == 200) {
    }
    else {
      throw Exception('Failed to load internet');
    }
    return listOfString;
  }

My Api Call 
[
    {
        "status": 200,
        "msg": "Ok",
        "rows": [
            {
                "lid": "11031",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            },
            {
               "lid": "11032",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            },
            {
                 "lid": "11034",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            }
        ],
        "sql": "gg",
        "reserved": null
    }
]

Answer 1

第 1 步： 为您的响应创建一个模型类 例如

示例 JSON 结构 //在你的响应结果中是行

{
    "count": 49,
    "next": null,
    "previous": null,
    "results": [{
        "id": 4,
        "name": "PC",
        "image_background": "https://media.rawg.io/media/games/562/562553814dd54e001a541e4ee83a591c.jpg"
    }]

}


class PlatformResult
{
  int count;
  String next;
  final List<Results> result;
  PlatformResult({this.count,this.next,this.result});
  factory PlatformResult.fromJson(Map<String, dynamic> json) {
    return PlatformResult(
      count: json['count'],
      next:json['next'],
      result: parseResult(json),
    );

  }
  static List<Results> parseResult(resultJson) {
    var list = resultJson['results'] as List;
    List<Results> resultsList =
    list.map((data) => Results.fromJson(data)).toList();
    return resultsList;
  }

}

class Results {
  final int id;
  final String name;
  final String image_background;
  Results({this.id, this.name,this.image_background});
  factory Results.fromJson(Map<String, dynamic> parsedJson) {
    return Results(id: parsedJson['id'], name: parsedJson['name'],image_background:parsedJson['image_background']

    );

}

第 2 步：

获取结果的函数：

PlatformResult platformResult;
getData(BuildContext context) async {
  var res = await http
      .get(Uri.encodeFull(url), headers: {"Accept": "application/json"});
  print(res.body);
  if (res.statusCode == 200) {
    print(res.body);
    platformResult = PlatformResult.fromJson(json.decode(res.body));
  }
  return  platformResult;
}

第 3 步：

使用 FutureBuilder 显示您的列表数据

   FutureBuilder(
            future:   getData(context),
            builder: (BuildContext context,AsyncSnapshot  platformData)
              {
               if (platformData.hasData != null) {
                    return ListView.builder(
                      shrinkWrap: true,
                      itemCount: platformData==null?0:   platformResult.result.length,
                      itemBuilder: (context, index) {
                        return Card(
                          child: Container(
                            child: Column(children: <Widget>[
                               Text('${platformResult.result[index].name}'),
                              new Container(
                                  width: 190.0,
                                  height: 190.0,
                                  decoration: new BoxDecoration(
                                      shape: BoxShape.circle,
                                      image: new DecorationImage(
                                          fit: BoxFit.fill,
                                          image: new NetworkImage(

                                            platformResult.result[index].image_background,
                                          )
                                      )
                                  )),

                            ],),

                          ),

                        );
                      },
                    );
                  }
                  else {

                    return Center(child: CircularProgressIndicator(
                        valueColor: AlwaysStoppedAnimation<Color>(
                            Colors.green)));
                  }

              };)

Answer 2

您可以在下面复制粘贴运行完整代码
假设您的响应 JSON 字符串是这样的，它是数组

[
    {
        "status": 200,
        "msg": "Ok",
        "rows": [
            {
                "lid": "11031",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            },
            {
               "lid": "11032",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            },
            {
                 "lid": "11034",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            }
        ],
        "sql": "gg",
        "reserved": null
    }
]

你可以用相关的类来解析

// To parse this JSON data, do
//
//     final payload = payloadFromJson(jsonString);

import 'dart:convert';

List<Payload> payloadFromJson(String str) => List<Payload>.from(json.decode(str).map((x) => Payload.fromJson(x)));

String payloadToJson(List<Payload> data) => json.encode(List<dynamic>.from(data.map((x) => x.toJson())));

class Payload {
    int status;
    String msg;
    List<Row> rows;
    String sql;
    dynamic reserved;

    Payload({
        this.status,
        this.msg,
        this.rows,
        this.sql,
        this.reserved,
    });

    factory Payload.fromJson(Map<String, dynamic> json) => Payload(
        status: json["status"],
        msg: json["msg"],
        rows: List<Row>.from(json["rows"].map((x) => Row.fromJson(x))),
        sql: json["sql"],
        reserved: json["reserved"],
    );

    Map<String, dynamic> toJson() => {
        "status": status,
        "msg": msg,
        "rows": List<dynamic>.from(rows.map((x) => x.toJson())),
        "sql": sql,
        "reserved": reserved,
    };
}

class Row {
    String lid;
    String companyName;
    String leadSourceName;
    String leadSourceValue;

    Row({
        this.lid,
        this.companyName,
        this.leadSourceName,
        this.leadSourceValue,
    });

    factory Row.fromJson(Map<String, dynamic> json) => Row(
        lid: json["lid"],
        companyName: json["CompanyName"],
        leadSourceName: json["LeadSourceName"],
        leadSourceValue: json["LeadSourceValue"],
    );

    Map<String, dynamic> toJson() => {
        "lid": lid,
        "CompanyName": companyName,
        "LeadSourceName": leadSourceName,
        "LeadSourceValue": leadSourceValue,
    };
}

并显示 ListView

loading == true
                ? CircularProgressIndicator()
                : Expanded(
                    flex: 1,
                    child: ListView.builder(
                        padding: const EdgeInsets.all(8),
                        itemCount: payloadList == null ? 0 : payloadList[0].rows.length,
                        itemBuilder: (BuildContext context, int index) {
                          return Container(
                            height: 50,
                            child: Center(
                                child: Text(
                                    'lid ${payloadList[0].rows[index].lid}')),
                          );
                        }),
                  ),

工作演示

完整代码

import 'package:flutter/material.dart';
// To parse this JSON data, do
//
//     final payload = payloadFromJson(jsonString);

import 'dart:convert';

List<Payload> payloadFromJson(String str) =>
    List<Payload>.from(json.decode(str).map((x) => Payload.fromJson(x)));

String payloadToJson(List<Payload> data) =>
    json.encode(List<dynamic>.from(data.map((x) => x.toJson())));

class Payload {
  int status;
  String msg;
  List<Row> rows;
  String sql;
  dynamic reserved;

  Payload({
    this.status,
    this.msg,
    this.rows,
    this.sql,
    this.reserved,
  });

  factory Payload.fromJson(Map<String, dynamic> json) => Payload(
        status: json["status"],
        msg: json["msg"],
        rows: List<Row>.from(json["rows"].map((x) => Row.fromJson(x))),
        sql: json["sql"],
        reserved: json["reserved"],
      );

  Map<String, dynamic> toJson() => {
        "status": status,
        "msg": msg,
        "rows": List<dynamic>.from(rows.map((x) => x.toJson())),
        "sql": sql,
        "reserved": reserved,
      };
}

class Row {
  String lid;
  String companyName;
  String leadSourceName;
  String leadSourceValue;

  Row({
    this.lid,
    this.companyName,
    this.leadSourceName,
    this.leadSourceValue,
  });

  factory Row.fromJson(Map<String, dynamic> json) => Row(
        lid: json["lid"],
        companyName: json["CompanyName"],
        leadSourceName: json["LeadSourceName"],
        leadSourceValue: json["LeadSourceValue"],
      );

  Map<String, dynamic> toJson() => {
        "lid": lid,
        "CompanyName": companyName,
        "LeadSourceName": leadSourceName,
        "LeadSourceValue": leadSourceValue,
      };
}

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  List<Payload> payloadList;
  bool loading = false;
  String jsonString = '''
  [
    {
        "status": 200,
        "msg": "Ok",
        "rows": [
            {
                "lid": "11031",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            },
            {
               "lid": "11032",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            },
            {
                 "lid": "11034",
                "CompanyName": "WALLS ICE CREAM",
                "LeadSourceName": "Website",
                "LeadSourceValue": "ONLINE ADS"
            }
        ],
        "sql": "gg",
        "reserved": null
    }
]
  ''';

  void _incrementCounter() {
    setState(() {
      loading = true;
      payloadList = payloadFromJson(jsonString);
      loading = false;
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            loading == true
                ? CircularProgressIndicator()
                : Expanded(
                    flex: 1,
                    child: ListView.builder(
                        padding: const EdgeInsets.all(8),
                        itemCount: payloadList == null ? 0 : payloadList[0].rows.length,
                        itemBuilder: (BuildContext context, int index) {
                          return Container(
                            height: 50,
                            child: Center(
                                child: Text(
                                    'lid ${payloadList[0].rows[index].lid}')),
                          );
                        }),
                  ),
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}