我在发送帖子请求时出现一个奇怪的错误。
// this map is passed to a function
final Map<String, dynamic> activityData = {
"userId": 1,
"name": activityName.text,
"description": activityDescription.text,
"startAt": activityStartAt.text,
"endsAt": activityEndAt.text,
"lat": _latitude,
"long": _longitude,
"category": 2,
"status": "pending"
};
// this code bellow is inside a async function
final http.Response response =
await http.post(Uri.encodeFull(url), body: activityData);
这是错误:
E/flutter (32582): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter (32582): type 'int' is not a subtype of type 'String' in type cast
E/flutter (32582): #0 CastMap.forEach.<anonymous closure> (dart:_internal/cast.dart:286:25)
E/flutter (32582): #1 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.forEach (dart:collection/runtime/libcompact_hash.dart:370:8)
E/flutter (32582): #2 CastMap.forEach (dart:_internal/cast.dart:285:13)
E/flutter (32582): #3 mapToQuery (package:http/src/utils.dart:17:7)
E/flutter (32582): #4 Request.bodyFields= (package:http/src/request.dart:128:17)
E/flutter (32582): #5 BaseClient._sendUnstreamed (package:http/src/base_client.dart:163:17)
E/flutter (32582): <asynchronous suspension>
E/flutter (32582): #6 BaseClient.post (package:http/src/base_client.dart:54:7)
E/flutter (32582): #7 post.<anonymous closure> (package:http/http.dart:70:16)
E/flutter (32582): #8 _withClient (package:http/http.dart:166:20)
E/flutter (32582): <asynchronous suspension>
E/flutter (32582): #9 post (package:http/http.dart:69:5)
E/flutter (32582): #10 _MainModel&Model&ConnectedModel&UsersModel&ActivitiesModel.createActivity (package:activmap/scoped-models/connectedModel.dart:62:15)
E/flutter (32582): <asynchronous suspension>
E/flutter (32582): #11 _NewActivityState.save (package:activmap/pages/newActivity.dart:271:11)
E/flutter (32582): <asynchronous suspension>
E/flutter (32582): #12 _NewActivityState.build.<anonymous closure> (package:activmap/pages/newActivity.dart:248:30)
E/flutter (32582): #13 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:507:14)
E/flutter (32582): #14 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:562:30)
E/flutter (32582): #15 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
E/flutter (32582): #16 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:242:9)
E/flutter (32582): #17 TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:175:7)
E/flutter (32582): #18 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:315:9)
E/flutter (32582): #19 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
E/flutter (32582): #20 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
E/flutter (32582): #21 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:180:19)
E/flutter (32582): #22 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:158:22)
E/flutter (32582): #23 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:138:7)
E/flutter (32582): #24 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:101:7)
E/flutter (32582): #25 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:85:7)
E/flutter (32582): #26 _invoke1 (dart:ui/hooks.dart:168:13)
E/flutter (32582): #27 _dispatchPointerDataPacket (dart:ui/hooks.dart:122:5)
我让它在另一个屏幕上正常工作,我可以看到的唯一区别是工作的那个只有字符串,而这个有 int、double 和字符串。
要解决您的问题,您只需在发送前对数据进行编码。
import 'dart:convert';
...
final http.Response response =
await http.post(Uri.encodeFull(url), body: json.encode(activityData));
如果您的 API 不支持 JSON,则只需将所有数据作为字符串传递即可。
final Map<String, dynamic> activityData = {
"user_id": "1",
"name": activityName.text,
"description": activityDescription.text,
"startAt": activityStartAt.text,
"endsAt": activityEndAt.text,
"lat": "$_latitude",
"long": "$_longitude",
"category": "2",
"status": "pending"
};
final http.Response response =
await http.post(Uri.encodeFull(url), body: activityData);
第 1 步:在标题中使用 "content-type": "application/json"
第 2 步:将您的身体编码为喜欢 jsonEncode( {"param1": 10, "param2":20,"param3": "abc","param4": true})
示例代码类似
headers: {
"content-type": "application/json",
},
body:jsonEncode( {
"qualificationId": 10,
"year":2001,
"instituteName": "example",
"isActive": true
})
签出请求 - 一个用于发出 http 请求的颤振库(灵感来自 python 请求模块)
发布application/x-www-form-urlencoded
:
var r = await Requests.post(
"https://reqres.in/api/users", body: {
"userId": 10,
"id": 91,
"title": "aut amet sed",
},
bodyEncoding: RequestBodyEncoding.FormURLEncoded);
r.raiseForStatus();
dynamic json = r.json();
print(json['id']);
发布application/json
:
var r = await Requests.post("https://reqres.in/api/users", json: {
"userId": 10,
"id": 91,
"title": "aut amet sed",
"body": "libero voluptate eveniet aperiam sednsunt placeat suscipit molestiasnsimilique fugit nam natusnexpedita consequatur consequatur dolores quia eos et placeat",
});
r.raiseForStatus();
dynamic body = r.json();
print(json['id']);
对于 flutter 版本 2.0.6
和 http dart 包^0.13.3
,您需要解析 URL 并使用 dart:convert 库中的json.encode
对有效负载进行编码,如下所示:
import 'package:http/http.dart' as http;
import 'dart:convert';
-------
var url = Uri.parse('http://10.0.2.2:8000/api/test');
var response = await http.post(url, body: json.encode({ 'name': 'mac', 'password': 'test' }));
print(response.body);