如何在react-native中使用FormData？

Question

嗨,只是学习使用js和react-native.我不能使用FormData它总是显示不支持的bodyinit类型.我想发送文本而不是json.stringfy.谁能帮我？谢谢!

var data = new FormData()
data.append('haha', 'input')

fetch('http://www.mywebsite.com/search.php', { 
  method: 'post',
  body: data
})
.then((response) => response.json())
.then((responseData) => {
  console.log('Fetch Success==================');
  console.log(responseData);

  var tempMarker = [];
  for (var p in responseData) {
   tempMarker.push({
    latitude: responseData[p]['lat'],
    longitude: responseData[p]['lng'] 
   })
  }

  this.setState({
    marker: tempMarker
  });

})
.catch((error) => {
  console.warn(error);
})
.done();

Answer 1

这是我的简单代码FormData with react-native to post request with string and image.

我已经使用react-native-image-picker来捕获/选择photo react-native-image-picker

let photo = { uri: source.uri}
let formdata = new FormData();

formdata.append("product[name]", 'test')
formdata.append("product[price]", 10)
formdata.append("product[category_ids][]", 2)
formdata.append("product[description]", '12dsadadsa')
formdata.append("product[images_attributes[0][file]]", {uri: photo.uri, name: 'image.jpg', type: 'image/jpeg'})

Answer 2

这对我有用

var serializeJSON = function(data) {
  return Object.keys(data).map(function (keyName) {
    return encodeURIComponent(keyName) + '=' + encodeURIComponent(data[keyName])
  }).join('&');
}

var response = fetch(url, {
  method: 'POST',
  body: serializeJSON({
    haha: 'input'
  })
});

Answer 3

如果要为 formData 项设置自定义内容类型：

var img = {
    uri : 'file://opa.jpeg',
    name: 'opa.jpeg',
    type: 'image/jpeg'
};
var personInfo = {
    name : 'David',
    age: 16
};

var fdata = new FormData();
fdata.append('personInfo', {
    "string": JSON.stringify(personInfo), //This is how it works :)
    type: 'application/json'
});

fdata.append('image', {
    uri: img.uri,
    name: img.name,
    type: img.type
});

Answer 4

提供其他解决方案; 我们也在用react-native-image-picker; 并且服务器端正在使用koa-multer; 这个设置运作良好:

UI

ImagePicker.showImagePicker(options, (response) => {
      if (response.didCancel) {}
      else if (response.error) {}
      else if (response.customButton) {}
      else {
        this.props.addPhoto({ // leads to handleAddPhoto()
          fileName: response.fileName,
          path: response.path,
          type: response.type,
          uri: response.uri,
          width: response.width,
          height: response.height,
        });
      }
    });

handleAddPhoto = (photo) => { // photo is the above object
    uploadImage({ // these 3 properties are required
      uri: photo.uri,
      type: photo.type,
      name: photo.fileName,
    }).then((data) => {
      // ...
    });
  }

客户

export function uploadImage(file) { // so uri, type, name are required properties
  const formData = new FormData();
  formData.append('image', file);

  return fetch(`${imagePathPrefix}/upload`, { // give something like https://xx.yy.zz/upload/whatever
    method: 'POST',
    body: formData,
  }
  ).then(
    response => response.json()
  ).then(data => ({
    uri: data.uri,
    filename: data.filename,
  })
  ).catch(
    error => console.log('uploadImage error:', error)
  );
}

服务器

import multer from 'koa-multer';
import RouterBase from '../core/router-base';

const upload = multer({ dest: 'runtime/upload/' });

export default class FileUploadRouter extends RouterBase {
  setupRoutes({ router }) {
    router.post('/upload', upload.single('image'), async (ctx, next) => {
      const file = ctx.req.file;
      if (file != null) {
        ctx.body = {
          uri: file.filename,
          filename: file.originalname,
        };
      } else {
        ctx.body = {
          uri: '',
          filename: '',
        };
      }
    });
  }
}