如何解决“ CORS策略：“ Access-Control-Allow-Origin”标头的值不等于提供的来源。”

Question

I am working on an ionic 3 Project. When i run the project on android i get the following error.

Access to XMLHttpRequest at 'https://baseurl.com/api' from origin 'file://' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The 'Access-Control-Allow-Origin' header has a value 'https://baseurl.com' that is not equal to the supplied origin.

I started getting this error from last week monday and until then it was working fine.

In the requests(POST/GET) i am using the following headers

headers.append('Content-Type', 'application/x-www-form-urlencoded');

or

headers.append('Content-Type', 'application/json');

According to the ionic documentation CORS Errors , what i understood was that there are changes has to be done from the server side. Is there anything can be done from the ionic side? What could be the issue?

Answer 1

Two problems with your issue. One is more simple, and one is that https://baseurl/api doesn't have a .com, or a .anything, so it is mostly invalid. The second that CORS is a necessary evil to deal with. You are going to have to set up a local server do deal with it, as some requests cannot be made by items being served by a file:// protocol. Local servers can be set up a variety of ways, depending on your situation. It would be helpful to explain how you are running it, and what tools you are using, so that we may be able to better help you.

Answer 2

The issue is due to a chrome update and for further details about the issue please refer This .

Update the 'Android System Webview' in google play store to the latest version and this issue will go away