Dart 服務端開發 文件上傳

clent端使用angular組件

upload_component.html

form id="myForm" method="POST" enctype="multipart/form-data">
    <input type="file" name="fileData"> <!-- file field -->
</form>
<span>{{progress}}</span>
<button  (click)="upload()">上傳</button>

upload_component.dart

import 'package:angular/angular.dart';
import 'package:angular_forms/angular_forms.dart';
import "dart:html";
@Component(
  selector: 'upload',
  templateUrl: 'upload_component.html',
  styleUrls: const ['upload_component.css'],
  directives: const [CORE_DIRECTIVES,formDirectives],
)
class UploadComponent{
 //表示文件上傳進度
  String progress;

  void upload(){
     // formDate 表示用於存儲html文件表單字段的對象    
   var formData = new FormData(querySelector("#myForm"));

   final request = new HttpRequest();
  //使用post方法
   request.open('POST', 'http://localhost:8080/upload');
   //監聽文件上傳進度
   request.upload.onProgress.listen((ProgressEvent e) {
     progress = (e.loaded*100/e.total).toInt().toString() + '%';
   });
   //監聽文件上傳完成時調用
   request.onLoad.listen((e) {
     print('Uploaded'+request.response);

   });
   
   request.send(formData);
  }

}

server端

import 'dart:io';

import 'package:mime/mime.dart';
import 'package:shelf/shelf.dart';
import 'package:shelf/shelf_io.dart' as io;
import 'package:shelf_cors/shelf_cors.dart';
import 'package:shelf_rest/shelf_rest.dart';

void main() {
  var rootRouter = router()..post('/upload',(Request request) async{

  print(request.headers);
  var header = HeaderValue.parse(request.headers['content-type']);
  await for(MimeMultipart part in request.read().transform(new MimeMultipartTransformer(header.parameters['boundary']))) {
  if(part.headers.containsKey('content-disposition')) {
  header = HeaderValue.parse(part.headers['content-disposition']);
  String filename = header.parameters['filename'];
  final file = new File(filename);
  IOSink fileSink = file.openWrite();
  await part.pipe(fileSink);
  fileSink.close();
  }
  }

  return new Response.ok("Success",headers:{'Access-Control-Allow-Origin':'*'});
  });
    //經過此中間件設置跨域標頭信息
  final cors = createCorsHeadersMiddleware(
      corsHeaders: {
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Expose-Headers': 'Authorization, Content-Type',
        'Access-Control-Allow-Headers': 'Authorization, Origin, X-Requested-With, Content-Type, Accept',
        'Access-Control-Allow-Methods': 'GET, POST, PUT, PATCH, DELETE'
      }
  );

  var handler = const Pipeline()
      .addMiddleware(logRequests())
      .addMiddleware(cors)  
      .addHandler(rootRouter.handler);

  printRoutes(rootRouter);

  io.serve(handler, 'localhost', 8080).then((server) {
    print('Serving at http://${server.address.host}:${server.port}');
  });
}