我想在我的颤振应用程序中使用转换API将word文件转换为pdf文件。com，我的POST方法有什么问题

Question

import 'dart:io';
import 'package:aconvert/pages/view.dart';
import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'dart:convert';
import 'dart:typed_data';
import 'package:aconvert/services/api.dart';
import 'package:path_provider/path_provider.dart';
import 'package:http/http.dart' as http;
import 'package:pdf_viewer_plugin/pdf_viewer_plugin.dart';

//final clientId = '2720faeb-aa0f-46ee-aa0a-8bf7559268fc';
//final secret = '65cc9d8e63d2a01be5dd5abde8cbc970';
//var configuration = Configuration(secret, clientId);
class Docx extends StatefulWidget {
  const Docx({Key? key}) : super(key: key);

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

class _DocxState extends State<Docx> {
//view pdf
  String? docFilePath;
  String? docFilename;
  String? docFiledata;
  File? _file;
  late final pathController = TextEditingController();


  pick_file() async{
    FilePickerResult? result = await FilePicker.platform.pickFiles(
      type: FileType.custom,
      allowedExtensions: ['doc','txt','TXT','png','jpg','pdf','PDF','rtf'],
    );

    if (result != null) {
      // List<File> files = result.paths.map((path) => File(path!)).toList();
      File file = File(result.files.single.path!);
      _file =  File(result.files.single.path!);
      setState(() {
        docFilePath =result.files.single.path!;
        docFilename = _file?.path.split('/').last;
        Uint8List? fileInByte = _file?.readAsBytesSync();
         docFiledata = base64Encode(fileInByte!);
         print("******** $docFilename **********");

      });

    } else {
      // User canceled the picker
    }
  }
  // convert to pdf api

  Future postfile() async{
    String url = 'https://v2.convertapi.com/convert/doc/to/pdf?Secret=5Wq3HMYGVzqViAXJ&Token=636106935&StoreFile=true';
    final Uri uri  = Uri.parse(url);
   http.Response response = await http.post(uri,body: {

       "Parameters": [
         {
           "Name": "File",
           "FileValue": {
             "Name": docFilename,
             "Data": docFiledata
           }
         },
         {
           "Name": "StoreFile",
           "Value": true
         }
       ]

    } , headers: {
      "Content-Type": "application/json"
    });
    var responsebody = json.decode(response.body) ;
   print('Response status: ${response.statusCode}');
    print('------------------------------------');
    print('Response body: ${response.body}');
    print('------------------------------------');
    print('Response body: ${responsebody}');

  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(
        title: Text('from docx to pdf'),
        titleTextStyle: TextStyle(color: Colors.white70 , fontSize: 25 , fontWeight: FontWeight.bold),
        backgroundColor: Colors.deepOrangeAccent,
        elevation: 0,
        centerTitle: true,
      ),
      body: SingleChildScrollView(

        child:Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            SizedBox(height: 20,),
            InkWell(
              onTap: pick_file,
              child: Container(
                  height: 60,
                  padding: EdgeInsets.all(10),
                  margin: EdgeInsets.all(10),

                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(20),
                    color: Colors.redAccent,
                  ),

                  child: Center(child: Text('select file ' ,style: TextStyle(fontSize: 30,color: Colors.white), ))),
            ),
            SizedBox(height: 20,),
            InkWell(
              onTap: (){
                Get.to(()=>View(docFilePath!));
              },
              child: Container(
                  height: 60,
                  padding: EdgeInsets.all(10),
                  margin: EdgeInsets.all(10),

                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(20),
                    color: Colors.redAccent,
                  ),

                  child: Center(child: Text('show selected file' ,style: TextStyle(fontSize: 30,color: Colors.white), ))),
            ),
            SizedBox(height: 20,),
                //convert
            InkWell(
              onTap: postfile,
              child: Container(
                  height: 60,
                  padding: EdgeInsets.all(10),
                  margin: EdgeInsets.all(10),

                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(20),
                    color: Colors.redAccent,
                  ),

                  child: Center(child: Text('convert' ,style: TextStyle(fontSize: 30,color: Colors.white), ))),
            ),
            SizedBox(height: 20,),
            InkWell(
              onTap: (){},
              child: Container(
                  height: 60,
                  padding: EdgeInsets.all(10),
                  margin: EdgeInsets.all(10),

                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(20),
                    color: Colors.redAccent,
                  ),

                  child: Center(child: Text('upload to cloud' ,style: TextStyle(fontSize: 30,color: Colors.white), ))),
            ),


          ],
        ),
      ),
    );
  }
}

E/flatter（11254）：[错误：flatter/lib/ui/ui_dart_state.cc（209）]未处理的异常：错误状态：无法设置属性类型为“application/json”的请求的正文字段。E/颤振（11254）：#0请求。bodyFields=（包：http/src/request.dart:133:7）E/flatter（11254）：#1 BaseClient_sendUnstreamed（包：http/src/base_client.dart:87:17）E/flatter（11254）：#2 BaseClient。post（包：http/src/base_client.dart:32:7）E/flatter（11254）：#3 post。（软件包：http/http.dart:69:16）E/flatter（11254）：#4_withClient（软件包：http/http.dart:164:20）E/flutter（11254）：第5篇文章。postfile（包：aconvert/pages/fromdocxtopdf.dart:61:40）E/flatter（11254）：#7_InkResponseState_handleTap（包：颤振/src/材料/墨水井。省道：989:21）E/颤振（11254）：#8手势识别器。调用调用回调（包：flatter/src/gestures/recognizer.dart:198:24）E/flatter（11254）：#9 TapgestureRecogizer。handleTapUp（软件包：flatter/src/signatures/tap.dart:608:11）E/flatter（11254）：#10基本姿势识别器_检查（包：颤振/src/手势/轻拍。省道：296:5）E/颤振（11254）：#11基本姿势识别器。handlePrimaryPointer（包：flatter/src/手势/轻拍。省道：230:7）E/flatter（11254）：#12初级指针检测识别器。handleEvent（软件包：颤振/src/手势/识别器。dart:563:9）E/颤振（11254）：#13指针输出器_调度（包：flatter/src/signatures/pointer_router.dart:94:12）E/flatter（11254）：#14 PointerRouter._dispatchEventToRoutes。（软件包：flatter/src/signatures/pointer_router.dart:139:9）E/flatter（11254）：#15_LinkedHashMapMixin。forEach（省道：收集补丁/压缩散列。省道：539:8）E/flatter（11254）：#16点路由器_dispatchEventToRoutes（包：flatter/src/手势/指针路由器。dart:137:18）E/flatter（11254）：#17指针路由器。路线（包：颤振/src/手势/指针_router.dart:123:7）E/颤振（11254）：#18手势绑定。handleEvent（包：颤振/src/手势/绑定。dart:439:19）E/颤振（11254）：#19手势绑定。dispatchEvent（包：flatter/src/手势/绑定。dart:419:22）E/flatter（11254）：#20渲染器绑定。调度事件（包：flatter/src/rendering/binding.dart:322:11）E/flatter（11254）：#21手势绑定_立即用手点（包：颤振/src/手势/绑定。省道：374:7）E/颤振（11254）：#22手势绑定。HandlePointeEvent（包：颤振/src/手势/绑定。dart:338:5）E/颤振（11254）：#23手势绑定_flushPointerEventQueue（包：flutter/src/手势/绑定。省道：296:7）E/flutter（11254）：#24手势绑定_handlePointerDataPacket（包：flatter/src/手势/绑定。dart:279:7）E/flatter（11254）：#25_rootRunUnary（dart:async/zone.dart:1442:13）E/flutter（11254）：26_CustomZone。RUNUARY（省道：异步/区域。省道：1335:19）E/颤振（11254）：#27_CustomZone。runUnaryGuarded（dart:async/zone.dart:1244:7）E/flutter（11254）：#28_invoke1（dart:ui/hooks.dart:170:10）E/Flatter（112 54）：35; 29 PlatformDispatcher_dispatchPointerDataPacket（dart:ui/platform_dispatcher.dart:331:7）E/Flatter（11254）：#30_DisPATchPointerData Packet

Answer 1

您需要用jsonEncode()包装主体

final body = {

       "Parameters": [
         {
           "Name": "File",
           "FileValue": {
             "Name": docFilename,
             "Data": docFiledata
           }
         },
         {
           "Name": "StoreFile",
           "Value": true
         }
       ]

    };

http.Response response = await http.post(
 uri, 
 body: jsonEncode(body), 
 headers: {"Content-Type": "application/json"}
);