使用 WebAPI 后端服务器处理新项目时，我无法从实际网站向 Controller 发送消息，尽管 Postman 向 Controller 发送消息没有问题。我收到错误 415，浏览器控制台记录:

HTTP415: UNSUPPORTED MEDIA TYPE - The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method.
(XHR)OPTIONS - http://localhost:5000/api/Users

虽然来自 Kestrel 的日志是

info: Microsoft.AspNetCore.Hosting.Internal.WebHost[1]
      Request starting HTTP/1.1 OPTIONS http://localhost:5000/api/Users  0
Microsoft.AspNetCore.Hosting.Internal.WebHost:Information: Request starting HTTP/1.1 OPTIONS http://localhost:5000/api/Users  0
info: Microsoft.AspNetCore.Mvc.StatusCodeResult[1]
      Executing HttpStatusCodeResult, setting HTTP status code 415
Microsoft.AspNetCore.Mvc.StatusCodeResult:Information: Executing HttpStatusCodeResult, setting HTTP status code 415
info: Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[2]
      Executed action SchoolsChat.Controllers.UserContoller.Post (SchoolsChat) in 2.5323ms
Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker:Information: Executed action SchoolsChat.Controllers.UserContoller.Post (SchoolsChat) in 2.5323ms
info: Microsoft.AspNetCore.Hosting.Internal.WebHost[2]
      Request finished in 6.6615ms 415 
Microsoft.AspNetCore.Hosting.Internal.WebHost:Information: Request finished in 6.6615ms 415 

我正在尝试发布以下 JSON:

{
    UserDOB: "2016-12-18",
    UserFirstName: "asdf",
    UserLastName: "asasdf",
    UserName: "asdf",
    UserSecret: "asdf"
}

使用这个 TypeScript 类

/**
 * JsonPost
 */
class JsonPost {
    private _response: number;
    public get Reponse(): number {
        return this._response;
    }
    constructor(link: string, data: Object) {
        let request = new XMLHttpRequest();
        request.withCredentials = true;

        request.open("POST", APIUri + link, true);
        request.setRequestHeader("content-type", "application/json");
        request.setRequestHeader("cache-control", "no-cache");
        request.onreadystatechange = () => this._response = request.status;
        console.log(request);
        request.send(JSON.stringify(data));
    }
}

User的模型是

public class User
    {
        [KeyAttribute]
        public int UserId { get; set; }
        [RequiredAttribute]
        public int SchoolId { get; set; }
        [RequiredAttribute]
        public string UserName { get; set; }
        [RequiredAttribute]
        [DataTypeAttribute(DataType.Password)]
        public string UserSecret { get; set; } // Unnecessary due to school linking?
        [RequiredAttribute]
        public virtual School UserSchool { get; set; }
    }

虽然发帖的 Controller 很简单，只是输出名字

[HttpPost]
    public IActionResult Post([FromBody]User user)
    {
        Console.WriteLine(user.UserName);
        return StatusCode(200);
    }

编辑 虽然 nemec 的回答有助于解决问题，但我发现对于 WebAPI，最好的解决方案是仅使用 app.UseCors 作为服务配置 cors。在许多情况下，AddCors 实际上并未在响应中包含必要的 header 。

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            app.UseCors(options => options.AllowAnyOrigin().AllowAnyHeader().AllowAnyMethod().AllowCredentials());
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();
            app.UseMvc();
        }

最佳答案

在我的例子中，问题是我在我的操作参数之前放置了一个 FromBody 属性。

来自:

[HttpPost("Contact")]
public async Task<IActionResult> NewContact([FromBody]Contact contact)

收件人:

[HttpPost("Contact")]
public async Task<IActionResult> NewContact(Contact contact)

关于c# - 使用 XMLHttpRequest 发布到 ASP.Net Core WebAPI 时出现错误 415，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41208452/