WebAPI为HttpGet抛出415错误

Question

我现在正在玩竹子.

我的[HttpGet]Web API 2控制器中有一个方法:

[HttpGet]
public LanguageResponse GetLanguages(LanguageRequest request) 
{
...
}

我的网址看起来像这样 http://localhost:1234/api/MyController/GetLanguages?Id=1

当尝试调用它时(例如,通过Postman),我收到HTTP错误415:

{"message":"The request contains an entity body but no Content-Type header. The inferred media type 'application/octet-stream' is not supported for this resource.","exceptionMessage":"No MediaTypeFormatter is available to read an object of type 'LanguagesRequest' from content with media type 'application/octet-stream'.","exceptionType":"System.Net.Http.UnsupportedMediaTypeException","stackTrace":"   at System.Net.Http.HttpContentExtensions.ReadAsAsync[T](HttpContent content, Type type, IEnumerable`1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)\r\n   at System.Web.Http.ModelBinding.FormatterParameterBinding.ReadContentAsync(HttpRequestMessage request, Type type, IEnumerable`1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)"}

这有点奇怪,因为我正在使用GET.

如果我添加Content-Type:application/json,则不会抛出异常,但是方法的request参数设置为null.

在我的客户端代码中,情况更糟.我无法设置Content-Type标题,因为我没有Content在我HttpRequestMessage的内容中,如果我设置内容,它会抱怨我使用了错误的动词.

Answer 1

正如在为什么我们必须在ASP.NET Web-API中指定FromBody和FromUri？,对于要从Uri解析的复杂模型,您必须使用您希望从请求Uri解析的参数的[FromUri]属性:

[HttpGet]
public LanguageResponse GetLanguages([FromUri] LanguageRequest request) 
{
    ...
}

否则,模型绑定器将抱怨缺少的Content-Type标头,因为它需要知道如何解析请求主体,无论如何在GET请求上丢失或为空.

要为具有正文(POST,PUT,...)的请求设置客户端的内容类型,请参阅如何为HttpClient请求设置Content-Type标头？.