无法让Relay通过网络进行GraphQL调用

我是Relay的新手，我在使用GraphQL服务器时遇到了问题 .

我已经将中继主页上的Tea样本改编为SWAPI中继服务 . 我克隆了swapi-graphql，并在快递服务器上添加了cors . 我用这段代码测试了链接：

var query = `
  {
    allFilms {
      edges {
        node {
          id
        }
      }
    }
  }
`

fetch("http://localhost:50515/graphiql?query=" + query)
  .then(response=>response.json())
  .then(json=>console.log(json))

我从服务器得到了回复，我看到了一些网络动作，它有效！我可以与graphiql服务进行通信 .

接下来，我创建了一个类似于TeaStoreQuery的查询结构 . 我tested它，它返回了预期的结果 .

query AllFilmQuery {
  allFilms {
    ...filmListFragment
  }
}

fragment filmListFragment on FilmsConnection {
  edges {
    node {
      ...filmFragment
    }
  }
}

fragment filmFragment on Film {
  id
  title
  releaseDate
}

HOW DO YOU MAKE THIS WORK WITH RELAY??

我无法弄清楚如何使用Relay来查询服务器 . 这是我从茶样本中改编的代码 .

import { render } from 'react-dom'
import { 
  RootContainer, 
  createContainer, 
  Route, 
  injectNetworkLayer 
} from 'react-relay'

// React component for each star wars film
const Film = ({ id, title, releaseDate }) => 
  <li key={id}>
    {title} (<em>{releaseDate}</em>)
  </li>

// Relay container for each film
const FilmContainer = createContainer(Film, {
  fragments: {
    film: () => Relay.QL`
      fragment on Film {
        id,
        title,
        releaseDate
      }
    `
  }
})               

// React component for listing films       
const FilmList = ({ films=[] }) => 
  <ul>
    {films.map(
      film => <Film {...film} />
    )}
  </ul>

// Relay container for Listing all Films
const FilmListContainer = createContainer(FilmList, {
  fragments: {
    films: () => Relay.QL`
      fragment on FilmsConnection {
        edges {
          node {
            ${ Film.getFragment('film') }
          }
        }
      }
    `
  }
})    

// The Home Route
class FilmHomeRoute extends Route {
  static routeName = 'Home'
  static queries = {
    allFilms: (Component) => Relay.QL`
      query AllFilmQuery {
        allFilms {
          ${Component.getFragment('allFilms')}
        }
      }
    `
  }
}

// Is this how you setup a network layer
// I am using CORS, and I testing the graphql service with fetch
// The graphql service works but Relay never seems to try to connect
Relay.injectNetworkLayer(
  new Relay.DefaultNetworkLayer('http://localhost:50515/graphiql')
)

render(
  <RootContainer
    Component={FilmListContainer}
    route={new FilmHomeRoute()}
  />,
  document.getElementById('react-container')
)

当我运行此示例（source | output）时，我没有看到任何尝试发出网络请求 . 我确实看到了错误"Cannot render map of null" . 好像它无法映射allfilms数据 .

我究竟做错了什么？