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
消息是明确的，“授权”是不允许在API。集 Access-Control-Allow-Headers: "Content-Type, Authorization"
其他回答
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
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。
当我们为请求定制报头时，会出现这个问题。此请求使用HTTP OPTIONS并包含几个头。
此请求所需的头是Access-Control-Request-Headers，它应该是响应头的一部分，并且应该允许来自所有源的请求。有时在响应头中也需要Content-Type。所以你的响应头应该是这样的
response.header("Access-Control-Allow-Origin", "*"); // allow request from all origin
response.header("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT");
response.header("Access-Control-Allow-Headers", "Access-Control-Allow-Headers, Origin, X-Requested-With, Content-Type, Accept, Authorization");
将这些头添加到ajax或js函数中
headers: {
"Cache-Control": null,
"X-Requested-With": null,
}
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)
