当我使用react-native init (RN版本0.29.1)创建一个全新的项目,并在渲染方法中获取公共facebook演示电影API时,它抛出了一个网络请求失败。有一个非常无用的堆栈跟踪,我不能调试网络请求在chrome控制台。这是我发送的fetch:

fetch('http://facebook.github.io/react-native/movies.json')
      .then((response) => response.json())
      .then((responseJson) => {
        return responseJson.movies;
      })
      .catch((error) => {
        console.error(error);
      });

当前回答

如果你在REST api中使用docker,我的一个工作案例是将主机名:http://demo.test/api替换为机器ip地址:http://x.x.x.x/api。你可以通过检查你的无线网络的ipv4来获取IP。你的手机也应该有wifi。

其他回答

Android用户:

Replace localhosts to a Lan IP addresses because when you run the project on an Android device, localhost is pointing to the Android device, instead of your computer, example: change http://localost to http://192.168.1.123 If your request URL is HTTPS and your Android device is under a proxy, assume you have installed User-added CA(like burp suite's CA or Charles's CA) in your Android device, make sure your Android version is below Nougat(7.0), because: Changes to Trusted Certificate Authorities in Android Nougat User-added CAs Protection of all application data is a key goal of the Android application sandbox. Android Nougat changes how applications interact with user- and admin-supplied CAs. By default, apps that target API level 24 will—by design—not honor such CAs unless the app explicitly opts in. This safe-by-default setting reduces application attack surface and encourages consistent handling of network and file-based application data.

对于Android设备,进入您的项目根文件夹并运行命令:

adb reverse tcp:[your_own_server_port] tcp:[your_own_server_port]

例如:adb reverse tcp:8088 tcp:8088

这将使您的物理设备(即。Android手机)监听本地主机服务器运行在您的开发机器(即您的计算机)地址http://localhost:[your_own_server_port]。

之后,你可以直接在react-native fetch()调用中使用http:localhost:[your_port] /your_api。

对于我们来说,这是因为我们正在上传一个文件,而RN filePicker没有给出正确的mime类型。它只是给了我们image作为类型。我们需要将其更改为'image/jpg'以使取回工作。

form.append(uploadFileName, {
  uri : localImage.full,
  type: 'image/jpeg',
  name: uploadFileName
 })

对于fetch API,你应该在.then中处理错误情况。

例如:

fetch(authURl,{ method: 'GET'})
.then((response) => {      
  const statusCode = response.status;
  console.warn('status Code',statusCode);
  if(statusCode==200){
    //success code
  }else{
    //handle other error code
  }      
},(err) => {
  console.warn('error',err)
})
.catch((error) => {
  console.error(error);
  return error;
});

这不是答案,而是选择。 我切换到https://github.com/joltup/rn-fetch-blob 它既适用于表单数据,也适用于文件