如何从web api中的angular post读取文件？

Question

I successfully implemented the OWIN based token authentication.

But before implementing this, when I try to get posted files multipart form data from my angular app to web api by using HttpContext.Current.Request.Files[i].FileName , then it easily gives me posted file that I want.

But after implementing owin based token authentication I am unable to get posted file and an error occurs on same line.

By spending more days on this error I have found most of the answers from internet but I still can't solve my problem.

And most of the solutions offered say that you cannot access HttpContext.Current.Request in a self-hosted container like

app.UseWebApi(config);

I am really stuck on this, so please help me.

The error is:

The line 306 is : HttpContext.Current.Request.Files[i].FileName

An error has occurred.
ExceptionMessage: This method or property is not supported after HttpRequest.GetBufferlessInputStream has been invoked.
ExceptionType: System.Web.HttpException
StackTrace
at System.Web.HttpRequest.EnsureFiles()
at System.Web.HttpRequest.get_Files()
at Nullplex.Rest.Controllers.UserBasicController.UpdateUserBasicByID(UserBasic UserBasic) in d:\\BitBucket\\PayBackRestApp \\Nullplex.Rest\\Controllers\\UserBasicController.cs:line 306
at lambda_method(Closure , Object , Object[] )
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.c__DisplayClass10 .b__9(Object instance, Object[] methodParameters)
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor .ActionExecutor.Execute(Object instance, Object[] arguments)
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor .ExecuteAsync(HttpControllerContext controllerContext, IDictionary2 arguments, CancellationToken cancellationToken )

End of stack trace from previous location where exception was thrown

at System.Runtime .CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\\r\\n at System.Runtime.CompilerServices .TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices .TaskAwaiter1.GetResult()
at System.Web.Http.Controllers.ApiControllerActionInvoker.d__0.MoveNext()

End of stack trace from previous location where exception was thrown

at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\\r\\n at System.Runtime .CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\\r\\n at System.Runtime .CompilerServices.TaskAwaiter1.GetResult()
at System.Web.Http.Controllers.ActionFilterResult. d__2.MoveNext()

Answer 1

I read file posted from angular in web api like this

if (!this.Request.Content.IsMimeMultipartContent("form-data"))
{
    var provider = new MultipartMemoryStreamProvider();
    await this.Request.Content.ReadAsMultipartAsync(provider);

    var content = provider.Contents.First();
    var buffer = await content.ReadAsByteArrayAsync();

now buffer contains the file data as byte[]