flask和react js文件上传不起作用 - javascript

我是python flask的新手，我在后端使用flask，在前端对js和pymongo进行反应，用于数据库。我想将文件从ReactJs上传到flask服务器，执行第二种方法时出现错误，我该怎么办。下面是我尝试过的代码。

我试过两个例子，一个正在工作，另一个不是我不知道为什么。

werkzeug.exceptions.BadRequestKeyError: 400 Bad Request: The browser (or proxy) sent a request that this server could not understand.
KeyError: 'file'

直接将文件发送到API。情况1

Python代码

import os
from flask import Flask, flash, request, redirect, url_for
from werkzeug.utils import secure_filename

UPLOAD_FOLDER = '/path/to/the/uploads'
ALLOWED_EXTENSIONS = set([ 'png', 'jpg', 'jpeg'])

app = Flask(__name__)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
@app.route('/api/users/add_photo', methods=['POST', "GET"])
def upload_file():
    if request.method == 'POST':
        # check if the post request has the file part
        if 'file' not in request.files:
            flash('No file part')
            return redirect(request.url)
        file = request.files['file']
        # if user does not select file, browser also
        # submit a empty part without filename
        if file.filename == '':
            flash('No selected file')
            return redirect(request.url)
        if file and allowed_file(file.filename):
            filename = secure_filename(file.filename)
            file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
            image = upload(open(filename, 'rb'))
            user_id = user.insert({"file":image})
            return jsonify({'result': "file Upload successfully!!!"})

onSubmitImage(e) {
    let file = this.state.file;
    let formData = new FormData();
    formData.append("file", file);
    this.props.imageUpload(formData);
  }

上面的例子运行良好

将文件发送到对象中的API。情况二

Python代码

import os
from flask import Flask, flash, request, redirect, url_for
from werkzeug.utils import secure_filename

UPLOAD_FOLDER = '/path/to/the/uploads'
ALLOWED_EXTENSIONS = set([ 'png', 'jpg', 'jpeg'])

app = Flask(__name__)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
@app.route('/api/users/add_photo', methods=['POST', "GET"])
def upload_file():
    if request.method == 'POST':
        # check if the post request has the file part
        if 'file' not in request.files:
            flash('No file part')
            return redirect(request.url)
        file = request.files['file']
        name = request.get_json(force=True)["name"]
        last_name = request.get_json(force=True)["last_name"]
        email = request.get_json(force=True)["email"]
        # if user does not select file, browser also
        # submit a empty part without filename
        if file.filename == '':
            flash('No selected file')
            return redirect(request.url)
        if file and allowed_file(file.filename):
            filename = secure_filename(file.filename)
            file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
            image = upload(open(filename, 'rb'))
            user_id = user.insert({"file":image,"name":name,"last_name":last_name,"email":email})
            return jsonify({'result': "file Upload successfully!!!"})

 onSubmitImage(e) {
    let file = this.state.file;
    let formData = new FormData();
    formData.append("file", file);
    const data = {
      file: formData
      name: this.state.name
      last_name: this.state.last_name
      email: this.state.last_name
    };
    this.props.imageUpload(data);
  }

我不知道为什么第一个有效，第二个无效。我想实现第二个示例，因为还有其他数据，例如名称，last_name，带有图像文件的电子邮件。

参考方案

您需要将数据添加到FormData（）-即

let file = this.state.file;
let formData = new FormData();
formData.append("file", file);
formData.append("name", this.state.name);
formData.append("last_name", this.state.last_name)
formData.append("email", this.state.last_name)
this.props.imageUpload(formData);

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