I have the following controller method which returns a byte array.
public async Task<HttpResponseMessage> Get()
{
var model = new byte[] { 1, 2, 3 };
HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK);
result.Content = new StreamContent(new MemoryStream(model));
result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
return result;
}
I think this is an older way of implementing this functionality with web api. Is there a more "modern" version?
For example, is returning a Task<IHttpActionResult> the preferred way now? And if so, what would be the code to return the byte array from above?
As the comment pointed out. I dont think there is a new way to do this. But if you would like to return an IHttpActionResult instead, there is a base method that returns a ResponseMessageResult:
public IHttpActionResult Get()
{
var model = new byte[] { 1, 2, 3 };
var result = new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new StreamContent(new MemoryStream(model))
};
result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
return ResponseMessage(result);
}
Also, to return binary data in AspNetCore WebApi2 if anyone needs it:
[Route("api/v1/export/excel")]
[HttpGet]
public IActionResult GetAsExcel()
{
var exportStream = new MemoryStream();
_exportService.ExportAllToExcel(exportStream);
// Rewind the stream before we send it.
exportStream.Position = 0;
return new FileStreamResult(exportStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
}
Related
A AuthorizedAttribute named as JwtAuthenticateAttribute is implemented and did something
It can be triggered for each request of the below API
[HttpGet]
[JwtAuthenticate]
public GetFaqListDS Index([FromUri] GetFaqListModel model)
{
List<MP_faqs> res = Faq.GetFaqList(model.curPage, model.pageSize);
var re = Request;
var hds = re.Headers;
GetFaqListDS ds = new GetFaqListDS();
ds.data = res;
return ds;
}
The question is, how to pass a value to this controller's function from the Attribute JwtAuthenticate.
P.S the value exists at the OnAuthorization of this attribute.
Thanks.
Add the required value in "actionContext.Request.Properties" in Onauthorize method and access these in controller.
Adding UserDetail Model :
actionContext.Request.Properties.Add("__user", new UserDetails(){userid=123, username="ABC"});
Retrieving values :
private static UserDetails GetUserDetailsFromRequest()
{
object tempVal;
try
{
var httpRequestMessage = (HttpRequestMessage)HttpContext.Current.Items["MS_HttpRequestMessage"];
httpRequestMessage.Properties.TryGetValue("__user", out tempVal);
if (tempVal == null) return null;
var user = (UserDetails)tempVal;
return user;
}
catch
{
}
return new UserDetails();
}
Hope this will helps you.
I'm developing the service within ASP.NET Boilerplate engine and getting the error from the subject. The nature of the error is not clear, as I inheriting from ApplicationService, as documentation suggests. The code:
namespace MyAbilities.Api.Blob
{
public class BlobService : ApplicationService, IBlobService
{
public readonly IRepository<UserMedia, int> _blobRepository;
public BlobService(IRepository<UserMedia, int> blobRepository)
{
_blobRepository = blobRepository;
}
public async Task<List<BlobDto>> UploadBlobs(HttpContent httpContent)
{
var blobUploadProvider = new BlobStorageUploadProvider();
var list = await httpContent.ReadAsMultipartAsync(blobUploadProvider)
.ContinueWith(task =>
{
if (task.IsFaulted || task.IsCanceled)
{
if (task.Exception != null) throw task.Exception;
}
var provider = task.Result;
return provider.Uploads.ToList();
});
// store blob info in the database
foreach (var blobDto in list)
{
SaveBlobData(blobDto);
}
return list;
}
public void SaveBlobData(BlobDto blobData)
{
UserMedia um = blobData.MapTo<UserMedia>();
_blobRepository.InsertOrUpdateAndGetId(um);
CurrentUnitOfWork.SaveChanges();
}
public async Task<BlobDto> DownloadBlob(int blobId)
{
// TODO: Implement this helper method. It should retrieve blob info
// from the database, based on the blobId. The record should contain the
// blobName, which should be returned as the result of this helper method.
var blobName = GetBlobName(blobId);
if (!String.IsNullOrEmpty(blobName))
{
var container = BlobHelper.GetBlobContainer();
var blob = container.GetBlockBlobReference(blobName);
// Download the blob into a memory stream. Notice that we're not putting the memory
// stream in a using statement. This is because we need the stream to be open for the
// API controller in order for the file to actually be downloadable. The closing and
// disposing of the stream is handled by the Web API framework.
var ms = new MemoryStream();
await blob.DownloadToStreamAsync(ms);
// Strip off any folder structure so the file name is just the file name
var lastPos = blob.Name.LastIndexOf('/');
var fileName = blob.Name.Substring(lastPos + 1, blob.Name.Length - lastPos - 1);
// Build and return the download model with the blob stream and its relevant info
var download = new BlobDto
{
FileName = fileName,
FileUrl = Convert.ToString(blob.Uri),
FileSizeInBytes = blob.Properties.Length,
ContentType = blob.Properties.ContentType
};
return download;
}
// Otherwise
return null;
}
//Retrieve blob info from the database
private string GetBlobName(int blobId)
{
throw new NotImplementedException();
}
}
}
The error appears even before the app flow jumps to 'SaveBlobData' method. Am I missed something?
Hate to answer my own questions, but here it is... after a while, I found out that if UnitOfWorkManager is not available for some reason, I can instantiate it in the code, by initializing IUnitOfWorkManager in the constructor. Then, you can simply use the following construction in your Save method:
using (var unitOfWork = _unitOfWorkManager.Begin())
{
//Save logic...
unitOfWork.Complete();
}
We are using asp.net web api in our application, in that we are trying to return the response with content-type with text/plain format but We are unable to succeeded. Same thing we tried with ASP.NET MVC it is working fine could you please provide me equivalent solution in Web API.
Please find below for the function implemented in ASP.NET MVC
public JsonResult FileUpload(HttpPostedFileBase file)
{
string extension = System.IO.Path.GetExtension(file.FileName);
string bufferData = string.Empty;
if (file != null)
{
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
byte[] array = ms.GetBuffer();
var appendInfo = "data:image/" + extension + ";base64,";
bufferData = appendInfo + Convert.ToBase64String(array);
}
}
var result = new
{
Data = bufferData
};
return Json(result,"text/plain");
}
Could you please suggest same implementation in WebAPI.
Thanks,
Bhagat
Web Api does the JSON work for you, so you can simplify your code handling on the endpoint. By default, you need to make changes in your WebApiConfig.cs for everything to work nicely. I've modified your method below:
public HttpResponseMessage FileUpload(HttpPostedFileBase file) {
var result = new HttpResponseMessage(HttpStatusCode.NotFound);
var bufferData = string.Empty;
try
{
if (file != null)
{
var extension = System.IO.Path.GetExtension(file.FileName);
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
var array = ms.GetBuffer();
var appendInfo = "data:image/" + extension + ";base64,";
bufferData = appendInfo + Convert.ToBase64String(array);
result.StatusCode = HttpStatusCode.OK;
// Set Headers and Content here
result.Content = bufferData;
}
}
}
catch(IOException ex)
{
// Handle IO Exception
}
return result
}
The changes you need to make in your WebApiConfig.cs could look like this:
public static void Register(HttpConfiguration config)
{
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}",
defaults: null,
constraints: new { action = #"\D+" }
);
// This makes the response default into JSON instead of XML
config.Formatters.Remove(config.Formatters.XmlFormatter);
}
As a note, the very fastest fix you can make to your code would be to do this, but I don't recommend returning strings.
public string FileUpload(HttpPostedFileBase file) {
var result = new HttpResponseMessage(HttpStatusCode.NotFound);
var bufferData = string.Empty;
if (file != null)
{
var extension = System.IO.Path.GetExtension(file.FileName);
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
var array = ms.GetBuffer();
var appendInfo = "data:image/" + extension + ";base64,";
bufferData = appendInfo + Convert.ToBase64String(array);
return bufferData;
}
}
// If you get here and have not returned,
// something went wrong and you should return an Empty
return String.Empty;
}
Good luck - there's lots of ways of handling files and file returns, so I want to assume you don't have some special return value on your handling.
I want to add a Location header to my http response when using webapi 2. The method below shows how to do this using a named route. Does anyone know if you can create the Url.Link using Attribute Routing feature that was released as part of webapi 2?
string uri = Url.Link("DefaultApi", new { id = reponse.Id });
httpResponse.Headers.Location = new Uri(uri);
Thanks in advance
You can use RouteName with Ur.Link when using attribute routing.
public class BooksController : ApiController
{
[Route("api/books/{id}", Name="GetBookById")]
public BookDto GetBook(int id)
{
// Implementation not shown...
}
[Route("api/books")]
public HttpResponseMessage Post(Book book)
{
// Validate and add book to database (not shown)
var response = Request.CreateResponse(HttpStatusCode.Created);
// Generate a link to the new book and set the Location header in the response.
string uri = Url.Link("GetBookById", new { id = book.BookId });
response.Headers.Location = new Uri(uri);
return response;
}
}
http://www.asp.net/web-api/overview/web-api-routing-and-actions/attribute-routing-in-web-api-2#route-names
You can do:
[Route("{id}", Name="GetById")]
public IHttpActionResult Get(int id)
{
// Implementation...
}
public IHttpActionResult Post([FromBody] UsuarioViewModel usuarioViewModel)
{
if (!ModelState.IsValid)
return BadRequest();
var link = Url.Link("GetById", new { id = 1});
var content = "a object";
return Created(link, content);
}
I need to write a Web API method that return result as CSS plain text and not the default XML or JSON, Is there a specific provider that I need to use?
I tried using the ContentResult class (http://msdn.microsoft.com/en-us/library/system.web.mvc.contentresult(v=vs.108).aspx) but no luck.
Thanks
You should bypass the content negotiation which means that you should return a new instance of HttpResponseMessage directly and set the content and the content type yourself:
return new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new StringContent(".hiddenView { display: none; }", Encoding.UTF8, "text/css")
};
Using the answers here as inspiration. You should be able to do something as simple as this:
public HttpResponseMessage Get()
{
string css = #"h1.basic {font-size: 1.3em;padding: 5px;color: #abcdef;background: #123456;border-bottom: 3px solid #123456;margin: 0 0 4px 0;text-align: center;}";
var response = new HttpResponseMessage(HttpStatusCode.OK);
response.Content = new StringContent(css, Encoding.UTF8, "text/css");
return response;
}
Can you return a HttpResponseMessage, get the file and just return the stream? Something like this seems to work....
public HttpResponseMessage Get(int id)
{
var dir = HttpContext.Current.Server.MapPath("~/content/site.css"); //location of the template file
var stream = new FileStream(dir, FileMode.Open);
var response = new HttpResponseMessage
{
StatusCode = HttpStatusCode.OK,
Content = new StreamContent(stream)
};
return response;
}
Although I would add some error checking in there if the file doesn't exist etc....
And just to pile on for fun, here's a version that would work under self-host too assuming you store the .css as an embedded file that sits in the same folder as the controller. Storing it in a file in your solution is nice because you get all the VS intellisense. And I added a bit of caching because chances are this resource isn't going to change much.
public HttpResponseMessage Get(int id)
{
var stream = GetType().Assembly.GetManifestResourceStream(GetType(),"site.css");
var cacheControlHeader = new CacheControlHeaderValue { MaxAge= new TimeSpan(1,0,0)};
var response = new HttpResponseMessage
{
StatusCode = HttpStatusCode.OK,
CacheControl = cacheControlHeader,
Content = new StreamContent(stream, Encoding.UTF8, "text/css" )
};
return response;
}
For anyone using AspNet Core WebApi you can simply do it like this
[HttpGet("custom.css")]
public IActionResult GetCustomCss()
{
var customCss = ".my-class { color: #fff }";
return Content(customCss, "text/css");
}