Web API 中提供了 HttpResponseMessage處理返回訊息，
HttpResponseMessage 用於返回一個來自於客戶端的請求結果訊息，你可以使用 HttpResponseMessage 自訂返回的內容，
另外HttpResponseException 則是以當發生例外時用來返回客戶端錯誤訊息，例如 Http Status 404 或 500。
在Web API 2 中提供了IHttpActionResult，判斷非同步建立 HttpResponseMessage 的命令。
直接看程式碼看如何使用吧。
舊 (WebApi):
public HttpResponseMessage DoSomething(int id)
{
var status = _Repository.doSomething(id);
if (status)
{
return new HttpResponseMessage(HttpStatusCode.OK);
}
else
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}
}
新 (WebApi2):
public IHttpActionResult DoSomething(int id)
{
var status = _Repository.doSomething(id);
if (status)
{
//return new HttpResponseMessage(HttpStatusCode.OK);
return Ok();
}
else
{
//throw new HttpResponseException(HttpStatusCode.NotFound);
return NotFound();
}
}
也可以把HttpResponseMessage 轉化成 IHttpActionResult回傳，
範例如下：
public IHttpActionResult SomeAction()
{
IHttpActionResult response;
//we want a 303 with the ability to set location
HttpResponseMessage responseMsg = new HttpResponseMessage(HttpStatusCode.RedirectMethod);
responseMsg.Headers.Location = new Uri("http://xxxxxx.blah");
response = ResponseMessage(responseMsg);
return response;
}
Reference:
https://msdn.microsoft.com/zh-tw/library/system.web.http.ihttpactionresult(v=vs.118).aspx
http://www.asp.net/web-api/overview/getting-started-with-aspnet-web-api/action-results