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
在尝试连接Django后端时，我也遇到了类似的问题:
在preflight响应中Access-Control-Allow-Headers不允许请求报头字段授权
经过几个小时的搜索，我终于在以下评论的帮助下解决了这个问题:
还要确保你拼写的授权是美式的，而不是英式的。那是我生命中的半小时，我不会再回来了。Thx美国!(叹息)
因此，给那些被卡住的人一个提示:检查一下你是否正确拼写了“Authorization”这个单词。如果你设置Access-Control-Allow-Headers = [" authorization "]，你就允许了错误的头!
在接下来的js我的问题得到解决使用
const cors=micro_cors({
origin:"https://studio.apollographql.com",
allowMethods:['POST','GET','PUT','PATCH','DELETE','OPTIONS'],
allowCredentials:true,
allowHeaders:['X-Requested-With','X-HTTP-Method-Override','Content-Type','Authorization','Accept','Access-Control-Allow-Credentials','Access-Control-Allow-Origin' ]
})
然后把它吸进去
export default cors(async function handler(req, res) {
await serverStart
if(req.method==="OPTIONS"){
res.end()
return false
}
apolloserver.createHandler({path:"/api/graphql"})(req,res)
})
我自己刚刚在ASP上下文中遇到了这个问题。NET确保您的Web。配置如下所示:
<system.webServer>
<modules>
<remove name="FormsAuthentication" />
</modules>
<handlers>
<remove name="ExtensionlessUrlHandler-Integrated-4.0" />
<!--<remove name="OPTIONSVerbHandler"/>-->
<remove name="TRACEVerbHandler" />
<!--
<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
-->
</handlers>
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Content-Type, Authorization" />
<add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE, OPTIONS" />
</customHeaders>
</httpProtocol>
注意Access-Control-Allow-Headers键的Authorization值。我错过了授权值，这个配置解决了我的问题。
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
这个问题用
"Origin, X-Requested-With, Content-Type, Accept, Authorization"
特别是在我的项目(express.js/nodejs)
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT");
res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization");
next();
});
更新:
每次错误:Access-Control-Allow-Headers本身在preflight响应错误中是不允许的，你可以看到chrome开发工具出了什么问题:
上面的错误是缺少Content-Type，所以添加字符串Content-Type到Access-Control-Allow-Headers
