请任何人告诉我以下三个模块如何在 asp.net Web API 2.1 中协同工作
我正在尝试做的是开发一个 web api,它将提供一个恒定格式的 json 数据,这意味着如果实际数据是
{"Id":1,"UserName":"abc","Email":"abc@xyz.com"}
然后我喜欢将 json 传递为
{__d:{"Id":1,"UserName":"abc","Email":"abc@xyz.com"}, code:200, somekey: "somevalue"}
为此,我尝试使用自定义 Action 过滤器属性 但我觉得(仍然无法确认)如果代码遇到异常,这将无法提供类似格式的数据
请建议我最好的方向。
这是我的自定义属性的简短代码片段。还建议我自定义属性是否适合此目的
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class, Inherited = true, AllowMultiple = false)]
public class ResponseNormalizationAttribute : ActionFilterAttribute
{
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
base.OnActionExecuted(actionExecutedContext);
var response = actionExecutedContext.Response;
object contentValue;
if (response.TryGetContentValue(out contentValue))
{
var nval = new { data=contentValue, status = 200 };
var newResponse = new HttpResponseMessage { Content = new ObjectContent(nval.GetType(), nval, new JsonMediaTypeFormatter()) };
newResponse.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
actionContext.Response = newResponse;
}
}
}
最佳答案
如果您不使用 Owin 中间件,您可以全局包装所有响应,以便使用委托(delegate)处理程序返回您的常量格式 json 数据。
编写一个继承自 DelegatingHandler 的自定义处理程序:
public class ApiResponseHandler : DelegatingHandler
{
protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
var response = await base.SendAsync(request, cancellationToken);
return BuildResponse(request, response);
}
private static HttpResponseMessage BuildResponse(HttpRequestMessage request, HttpResponseMessage response)
{
object content;
string errorMessage = null;
if (response.TryGetContentValue(out content) && !response.IsSuccessStatusCode)
{
HttpError error = content as HttpError;
if (error != null)
{
content = null;
errorMessage = error.Message;
}
}
var newResponse = request.CreateResponse(response.StatusCode, new ApiResponse((int)response.StatusCode, content, errorMessage));
foreach (var header in response.Headers)
{
newResponse.Headers.Add(header.Key, header.Value);
}
return newResponse;
}
}
//ApiResponse is your constant json response
public class ApiResponse
{
public ApiResponse(int statusCode, object content, string errorMsg)
{
Code = statusCode;
Content = content;
Error = errorMsg;
Id = Guid.NewGuid().ToString();
}
public string Error { get; set; }
//your actual data is mapped to the Content property
public object Content { get; set; }
public int Code { get; private set; }
public string Id { get; set; }
}
在
WebApiConfig.cs
中注册处理程序: public static void Register(HttpConfiguration config)
{
// Web API routes
config.MapHttpAttributeRoutes();
...
config.MessageHandlers.Add(new ApiResponseHandler());
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
...
}
我在 SO 中发布了一个类似的答案,但这是在 .NET Core 中并作为 OWIN 中间件实现(因为 DelegatingHandler 在 .NET Core 中消失了)。 How can I wrap Web API responses(in .net core) for consistency?
关于asp.net - Owin 中间件 vs ExceptionHandler vs HttpMessageHandler (DelegatingHandler),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24156853/