title: how send file with request in flutter
body: <p>hi guys i stack in this i used 2 packages http and dio and after 2 days of trying codes i don't find one work 
  so i used that with packag dio i wanna send file with request </p>
  
  <p>the problem is here ""dio.post(""   they don't find post in the package  </p>
  
  <pre><code>import 'package:dio/dio.dart' as dio;
  
  dio.FormData formData=new dio.FormData.fromMap({
    "file": await dio.MultipartFile.fromFile(imagePath,filename: imageName),
    "description": "fghfghfghfgh",
    "type": "Profile",
    "selected": "YES",
    "category_id": "3",
  });
  dio.Response response= await dio.post("https://top-food.coders-ries/images/create", body: formData);
  </code></pre>