问如何使用react-native将文件上传到服务器

EN

var photo = {
    uri: uriFromCameraRoll,
    type: 'image/jpeg',
    name: 'photo.jpg',
};

var body = new FormData();
body.append('authToken', 'secret');
body.append('photo', photo);
body.append('title', 'A beautiful photo!');

var xhr = new XMLHttpRequest();
xhr.open('POST', serverURL);
xhr.send(body);

const file = {
  uri,             // e.g. 'file:///path/to/file/image123.jpg'
  name,            // e.g. 'image123.jpg',
  type             // e.g. 'image/jpg'
}

const body = new FormData()
body.append('file', file)

fetch(url, {
  method: 'POST',
  body
})