C＃的Web API和CORS启用和可怕否“访问控制允许来源”标头的请求的资源present [英] c# Web Api with CORS Enabled and the dreaded No 'Access-Control-Allow-Origin' header is present on the requested resource

问题描述

我有一个C＃的Web API项目。我创建了使用Web API 2标准的控制器。我想只有一个动作使CORS，这是我有：

I have a C# Web API project. I created a Controller using the Web API 2 standard. I am trying to enable CORS on only one action, this is what I have:

namespace MyProject.Controllers
{
    public class MyControllerController : ApiController
    {
        // POST api/mycontroller
        [EnableCors("http://link.myurl.com", "*", "*")]
        public bool Post(MyCustomObject customObject)
        {
            // Function that returns Bool
            return myFunction(customObject);
        }
    }
}

我WebApiConfig.cs看起来是这样的：

My WebApiConfig.cs looks like this:

// Web API configuration and services
config.EnableCors(); 

// Web API routes
config.MapHttpAttributeRoutes();

config.Routes.MapHttpRoute(
     name: "DefaultApi",
     routeTemplate: "api/{controller}/{id}",
     defaults: new { id = RouteParameter.Optional }
);

// Ignore Null values on JSON Returns
config.Formatters.JsonFormatter.SerializerSettings = new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore };
config.Formatters.JsonFormatter.SerializerSettings = new JsonSerializerSettings { DefaultValueHandling = DefaultValueHandling.Ignore };

下面是跨域AJAX调用：

Here is the Cross-Domain AJAX call:

$.ajax({
    type: "POST",
    url: 'http://myurl.com/api/mycontroller',
    data: JSON.stringify({ Type: 'TextHere', OtherInfo: 'TextHere' }),
    contentType: "application/json",
    success: function (data) {
    }
});

根据关教程像这样的：<一href=\"http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api#how-it-works\" rel=\"nofollow\">http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api#how-it-works,我应该拥有的一切正确设置。

Based off tutorials such as this one: http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api#how-it-works, I should have everything properly setup.

我继续得到以下错误在Chrome中：

I continue to get the following error in Chrome:

XMLHtt prequest无法加载 http://myurl.com/api/mycontroller 。没有
  访问控制允许来源标头present的要求
  资源。因此出身 http://link.myurl.com '是不允许的
  访问。

XMLHttpRequest cannot load http://myurl.com/api/mycontroller. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://link.myurl.com' is therefore not allowed access.

当我看看使用招的电话，我注意到pre-航班始发地检查经过精细与状态200，但是当实际调用时返回500。

When I take a look at the calls using Fiddler, I notice that the Pre-flight Origin check goes through fine with Status 200, but when the actual call is made it returns 500.

有趣的是，交易被提交到数据库，即使调用失败。这几乎就像在pre-航班始发地检查通过时，它应该只检查允许原产code运行。

我试着加入以下的web.config：

I've tried adding the following to web.config:

<system.webServer>
   <httpProtocol>
     <customHeaders>
       <add name="Access-Control-Allow-Origin" value="http://link.myurl.com" />
     </customHeaders>
   </httpProtocol>
 <system.webServer>

如果我离开[EnableCors]行，然后我得到这两个值指定一个错误（的http：//链接。 myurl.com ）时只能有一个。如果我删除[EnabledCors]行，我得到原来的错误。

If I leave the [EnableCors] line, then I get an error that two values are specified (http://link.myurl.com) when there can only be one. If I remove the [EnabledCors] line, I get the original error.

如果您已经不能说，我不知所措就在这里。具有讽刺意味的​​是工作（数据库操作正在实施），但浏览器认为它不工作，从来没有接受JSON返回数据。

If you can't already tell, I'm at a loss here. Ironically it is working (database actions being committed), but the browser thinks its not working and never accepts the JSON return data.

帮助？

推荐答案

我不知道为什么，这周围的工作这段时间，但我得到了它的工作。主要的区别可能是我安装使用的NuGet库：

I'm not sure why this worked this time around, but I got it working. The main difference might be the library I installed using NuGet:

微软的ASP.NET Web API 2.2跨域支持

我然后设置WebApiConfig.cs文件，如我最初的职位说明，以及我想允许它在行动上面EnableCors选项。

I then set the WebApiConfig.cs file as specified in my initial post, as well as the EnableCors option above the Action I wanted to allow it on.

我没有设置在web.config文件中任何事情。

I did NOT set anything in the web.config file.

我不再收到错误，必须有一些做的的NuGet包。

I no longer receive the error, must have something to do with the NuGet package.

这篇关于C＃的Web API和CORS启用和可怕否“访问控制允许来源”标头的请求的资源present的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！