Flask设置允许跨域(Access to XMLHttpRequest 、CORS policy、Access-Control-Allow-Origin)

报错描述：

Access to XMLHttpRequest at 'http://******' from origin 'null' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

后台是flask，解决办法：需要设置flask允许跨域

Flask配Cors跨域,使用flask-cors包,并有两种方式

安装包：pip install flask-cors

from flask import Flask
from flask_cors import cross_origin

app = Flask(__name__)


@app.route('/', methods=['GET', 'POST'])
@cross_origin()
def hello_world():
    return 'hello world'


if __name__ == '__main__':
    app.run()