如何在flutter中使用表单数据制作http post？

Question

我正在尝试执行 http post 请求，我需要将正文指定为 form-data，因为服务器不将请求视为原始请求。

这就是我正在做的事情：

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {

  postTest() async {
    final uri = 'https://na57.salesforce.com/services/oauth2/token';
    var requestBody = {
      'grant_type':'password',
      'client_id':'3MVG9dZJodJWITSviqdj3EnW.LrZ81MbuGBqgIxxxdD6u7Mru2NOEs8bHFoFyNw_nVKPhlF2EzDbNYI0rphQL',
      'client_secret':'42E131F37E4E05313646E1ED1D3788D76192EBECA7486D15BDDB8408B9726B42',
      'username':'[email protected]',
      'password':'ABC1234563Af88jesKxPLVirJRW8wXvj3D'
    };

    http.Response response = await http.post(
        uri,
        body: json.encode(requestBody),
    );

    print(response.body);
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Container(
        child: Center(
          child: RaisedButton(
            child: Text('Press Here'),
            onPressed: (){
              postTest();
            },
          ),
        ),
      ),
    );
  }
}

这是实际的回应：

{
    "error": "unsupported_grant_type",
    "error_description": "grant type not supported"
}

这是预期的回应：

{
    "access_token": "00D0b000000Bb08!AR8AQO.s8mAGXCbwV77FXNLQqc2vtl8g6_16miVbgWlQMsuNHsaf2IGLUwnMVXBOfAj19iznhqhwlPOi4tagvf7FFgiJJgoi",
    "instance_url": "https://na57.salesforce.com",
    "id": "https://login.salesforce.com/id/00D0b000000Bb08EAC/0050b000005nstiAAA",
    "token_type": "Bearer",
    "issued_at": "1567993324968",
    "signature": "1+Zd/dSh9i7Moh2U0nFJLdXkVHqPlPVU6emwdYzXDPk="
}

您可以在邮递员上测试这一点，在raw（您得到实际响应）和form-data（您得到预期响应）之间切换主体

PS：标头是客户端工具创建的临时标头。

Answer 1

请使用 Map 代替，因为 http 包中的 body 只有 3 种类型：

String

、

List<int>

或

Map<String, String>

。

试试这个：

final Uri uri = Uri.parse('https://na57.salesforce.com/services/oauth2/token');
    final map = <String, dynamic>{};
    map['grant_type'] = 'password';
    map['client_id'] = '3MVG9dZJodJWITSviqdj3EnW.LrZ81MbuGBqgIxxxdD6u7Mru2NOEs8bHFoFyNw_nVKPhlF2EzDbNYI0rphQL';
    map['client_secret'] = '42E131F37E4E05313646E1ED1D3788D76192EBECA7486D15BDDB8408B9726B42';
    map['username'] = '[email protected]';
    map['password'] = 'ABC1234563Af88jesKxPLVirJRW8wXvj3D';

http.Response response = await http.post(
    uri,
    body: map,
);

Answer 2

使用 MultipartRequest 类

multipart/form-data 请求会自动将 Content-Type 标头设置为 multipart/form-data。

该值将覆盖用户设置的任何值。

请参阅 pub.dev 文档 此处

例如：

 Map<String, String> requestBody = <String,String>{
     'field1':value1
  };
 Map<String, String> headers= <String,String>{
     'Authorization':'Basic ${base64Encode(utf8.encode('user:password'))}'
  };

  var uri = Uri.parse('http://localhost.com');
  var request = http.MultipartRequest('POST', uri)
    ..headers.addAll(headers) //if u have headers, basic auth, token bearer... Else remove line
    ..fields.addAll(requestBody);
  var response = await request.send();
  final respStr = await response.stream.bytesToString();
  return jsonDecode(respStr);

希望这有帮助

Answer 3

有一个dart包dio
它就像一个魅力，我用它作为执行 http 请求的标准。
请阅读文档，了解如何使用 dio 包发送表单数据

import 'package:dio/dio.dart';    

postData(Map<String, dynamic> body)async{    
var dio = Dio();
try {
      FormData formData = new FormData.fromMap(body);
      var response = await dio.post(url, data: formData);
      return response.data;
    } catch (e) {
      print(e);
    }
}

Answer 4

那么，您想将正文作为表单数据发送，对吗？也许你可以试试这个？对我来说这是工作

postTest() async {
    final uri = 'https://na57.salesforce.com/services/oauth2/token';
    var requestBody = {
      'grant_type':'password',
      'client_id':'3MVG9dZJodJWITSviqdj3EnW.LrZ81MbuGBqgIxxxdD6u7Mru2NOEs8bHFoFyNw_nVKPhlF2EzDbNYI0rphQL',
      'client_secret':'42E131F37E4E05313646E1ED1D3788D76192EBECA7486D15BDDB8408B9726B42',
      'username':'[email protected]',
      'password':'ABC1234563Af88jesKxPLVirJRW8wXvj3D'
    };

    http.Response response = await http.post(
        uri,
        body: requestBody,
    );

    print(response.body);
  }

或者

postTest() async {
    final uri = 'https://na57.salesforce.com/services/oauth2/token';

    http.Response response = await http.post(
        uri, body: {
      'grant_type':'password',
      'client_id':'3MVG9dZJodJWITSviqdj3EnW.LrZ81MbuGBqgIxxxdD6u7Mru2NOEs8bHFoFyNw_nVKPhlF2EzDbNYI0rphQL',
      'client_secret':'42E131F37E4E05313646E1ED1D3788D76192EBECA7486D15BDDB8408B9726B42',
      'username':'[email protected]',
      'password':'ABC1234563Af88jesKxPLVirJRW8wXvj3D'
    });

    print(response.body);
  }

Answer 5

编辑 1（这适用于代码登录流程）：

String url = "https://login.salesforce.com/services/oauth2/token";
http.post(url, body: {
  "grant_type": "authorization_code",
  "client_id": "some_client_id",
  "redirect_uri": "some_redirect_uri",
  "code": "some_code_generated_by_salesforce_login",
  "client_secret": "some_client_secret",
}).then((response) {
  //--handle response
});

尝试一下“FormData”：

import 'package:dio/dio.dart';

FormData formData = new FormData.fromMap(dataMap);

retrofitClient.getToken(formData).then((response){//--handle respnse--});

“retrofitClient”来自包 改造：^1.0.1+1

Answer 6

你能试试这个吗；

    String url = 'https://myendpoint.com';
      Map<String, String> headers = {
"Content-Type": "application/x-www-form-urlencoded"    
"Content-type": "application/json"};
      String json = '{"grant_type":"password",
        "username":"[email protected]",
        "password":"123456"}';
      // make POST request
      Response response = await post(url, headers: headers, body: json);
      // check the status code for the result
      int statusCode = response.statusCode;
      // this API passes back the id of the new item added to the body
      String body = response.body;

Answer 7

这是我的表单数据功能示例

 Future<ResponseModel> postWithFormData(String url, List<File> files,
      {Map<String, String> body = const {}, bool throwAlert = false}) async {
    var request = http.MultipartRequest("POST", Uri.parse(localApiHost + url));

    request.headers
        .addAll({"Authorization": "Bearer ${Storage.getString(token)}"});
    request.fields.addAll(body);
    for (var file in files) {
      request.files.add(await http.MultipartFile.fromPath("files", file.path));
    }
    var sendRequest = await request.send();
    var response = await http.Response.fromStream(sendRequest);
    final responseData = json.decode(response.body);
    if (response.statusCode >= 400 && throwAlert) {
      showErrorDialog(responseData["message"]);
    }
    return ResponseModel(body: responseData, statusCode: response.statusCode);
  }

Answer 8

此代码片段成功执行了 POST api 调用，该调用需要授权令牌和表单数据。

final headers = {'Authorization': 'Bearer $authToken'};
  var requestBody = {
    'shopId': '5',
    'fromDate': '01/01/2021',
    'toDate': '01/10/2022',
  };

  final response = await http.post(
    Uri.parse(
        'https://api.sample.com/mobile/dashboard/getdetails'),
    headers: headers,
    body: requestBody,
  );

  print("RESPONSE ${response.body}");

Answer 9

使用POSTMAN测试查询并获取格式非常有用。这可以让您查看是否确实需要设置标题。请参阅下面我的示例。我希望它能有所帮助，而且不会太多

import 'dart:convert';
import 'package:http/http.dart';

class RegisterUser{    
  String fullname;
  String phonenumber;
  String emailaddress;
  String password;
  Map data;    
  RegisterUser({this.fullname, this.phonenumber, this.emailaddress, this.password});    
  Future<void> registeruseraction() async {    
    String url = 'https://api.url.com/';
    Response response = await post(url, body: {
      'fullname' : fullname,
      'phonenumber' : phonenumber,
      'emailaddress' : emailaddress,
      'password' : password
    });    
    print(response.body);
    data = jsonDecode(response.body);    
  }    
}

Answer 10

你也可以使用MultiPartRequest，它肯定会工作

  var request = new 
  http.MultipartRequest("POST",Uri.parse("$baseUrl/example/"));

  request.headers.addAll(baseHeader);
  request.fields['id'] = params.id.toString();
  request.fields['regionId'] = params.regionId.toString();
  request.fields['districtId'] = params.districtId.toString(); 
  http.Response response = await http.Response.fromStream(await 
  request.send());

  print('Uploaded! ${response.body} ++ ${response.statusCode}');
 

Answer 11

import 'package:http/http.dart' as http;

// Function to make the POST request
Future<http.Response> post(String url, Map<String, String> body) async {
  // Encode the body of the request as JSON
  var encodedBody = json.encode(body);

  // Make the POST request
  var response = await http.post(url,
      headers: {"Content-Type": "application/json"}, body: encodedBody);

  // Return the response
  return response;
}