我曾多次遇到CORS问题,通常可以解决它,但我想通过从MEAN堆栈范式中看到这一点来真正理解。

之前我只是在我的快速服务器中添加了中间件来捕获这些东西,但它看起来像有某种预挂钩,使我的请求出错。

在preflight响应中,Access-Control-Allow-Headers不允许请求报头字段Access-Control-Allow-Headers

我假设我可以这样做:

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Headers","*")
})

或者等价的,但这似乎不能解决问题。我当然也试过

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Headers","Access-Control-Allow-Headers")
})

还是不走运。


当前回答

这是你需要添加的使它工作。

response.setHeader("Access-Control-Allow-Origin", "*");
response.setHeader("Access-Control-Allow-Credentials", "true");
response.setHeader("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT");
response.setHeader("Access-Control-Allow-Headers", "Access-Control-Allow-Headers, Origin,Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");

The browser sends a preflight request (with method type OPTIONS) to check if the service hosted on the server is allowed to be accessed from the browser on a different domain. In response to the preflight request if you inject above headers the browser understands that it is ok to make further calls and i will get a valid response to my actual GET/POST call. you can constraint the domain to which access is granted by using Access-Control-Allow-Origin", "localhost, xvz.com" instead of * . ( * will grant access to all domains)

其他回答

在花了差不多一天的时间后,我才发现添加下面两个代码解决了我的问题。

将此添加到Global.asax中

protected void Application_BeginRequest()
{
  if (Request.HttpMethod == "OPTIONS")
  {
    Response.StatusCode = (int)System.Net.HttpStatusCode.OK;             
    Response.End();
  }
}

并在web配置中添加以下内容

<httpProtocol>
  <customHeaders>
    <add name="Access-Control-Allow-Origin" value="*" />        
    <add name="Access-Control-Allow-Methods" value="*" />
    <add name="Access-Control-Allow-Headers" value="Content-Type, Authorization" />
  </customHeaders>
</httpProtocol>

铬:

请求头字段X-Requested-With不被允许 预飞行响应中的Access-Control-Allow-Headers。

对我来说,此错误是由此调用的URL中的尾随空格触发的。

jQuery.getJSON( url, function( response, status, xhr ) {
   ...
}

我刚刚添加了response。headers;后

http.Response response = await http.get(
        Uri.parse(
          api + "api/users/all",
        ),
      );

CORS设置在后端(Django)作为官方文档, Djnago-cors-headers

是的,在集成angular应用程序时,我也面临着这个问题。

写这篇文章。

app.use((req, res, next) => {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader(
    "Access-Control-Allow-Headers",
    "Origin,X-Requested-With, Content-Type, Accept, Authorization"
  );
  res.setHeader("Access-Control-Allow-Methods", "GET,POST,PATCH,PUT,DELETE,OPTIONS");
  next();
});

跟我来谢谢

再补充一点,你也可以把这些头文件放到Webpack配置文件中。我需要他们在我的情况下,因为我正在运行webpack开发服务器。

devServer: {
    headers: {
      "Access-Control-Allow-Origin": "*",
      "Access-Control-Allow-Credentials": "true",
      "Access-Control-Allow-Methods": "GET,HEAD,OPTIONS,POST,PUT",
      "Access-Control-Allow-Headers": "Origin, X-Requested-With, Content-Type, Accept, Authorization"
    }
},