File upload with React component and dotnet core web API controller

react.js

// Based on https://gist.github.com/AshikNesin/e44b1950f6a24cfcd85330ffc1713513

import React from 'react'
import { post } from 'axios';

class UploadForm extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      id: 'get-id-from-somewhere',
      file: null,
    };
  }

  async submit(e) {
    e.preventDefault();

    const url = `http://target-url/api/${this.state.id}`;
    const formData = new FormData();
    formData.append('body', this.state.file);
    const config = {
      headers: {
        'content-type': 'multipart/form-data',
      },
    };
    return post(url, formData, config);
  }

  setFile(e) {
    this.setState({ file: e.target.files[0] });
  }

  render() {
    return (
      <form onSubmit={e => this.submit(e)}>
        <h1>File Upload</h1>
        <input type="file" onChange={e => this.setFile(e)} />
        <button type="submit">Upload</button>
      </form>
    );
  }
}

UploadController.cs

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace Demo.Web.Controllers
{
    public class UploadController : Controller
    {
        [HttpPost]
        [Route("{id:Guid}")]
        public async Task<IActionResult> Post([FromRoute]Guid id, [FromForm]IFormFile body)
        {
            byte[] fileBytes;
            var filePath = Path.Combine(_config["StoredFilesPath"], Path.GetRandomFileName());
            using (var stream = System.IO.File.Create(filePath))
            {
                await formFile.CopyToAsync(stream);
            }

            var filename = body.FileName;
            var contentType = body.ContentType;
            
            //save a reference to the file to your database
            _repo.addImage(fileName, filePath, contentType)

            return Ok();
        }
    }
}