When a business manager invests in new or modified software, he or she expects business results from that investment. Sadly, more often than not, they don't get that. They may get a technically brilliant system, but if that system's architecture isn't based on the architecture of the business, or on business goals and strategy – then it's still a failure.
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
// Web API configuration and services
// Web API routes
config.MapHttpAttributeRoutes();
}
} public class VideoStream
{
private readonly string _filename;
private long _contentLength;
public long FileLength
{
get { return _contentLength; }
}
public VideoStream(string videoPath)
{
_filename = videoPath;
using (var video = File.Open(_filename, FileMode.Open, FileAccess.Read, FileShare.Read))
{
_contentLength = video.Length;
}
}
public async void WriteToStream(Stream outputStream,
HttpContent content, TransportContext context)
{
try
{
var buffer = new byte[65536];
using (var video = File.Open(_filename, FileMode.Open, FileAccess.Read, FileShare.Read))
{
var length = (int)video.Length;
var bytesRead = 1;
while (length > 0 && bytesRead > 0)
{
bytesRead = video.Read(buffer, 0, Math.Min(length, buffer.Length));
await outputStream.WriteAsync(buffer, 0, bytesRead);
length -= bytesRead;
}
}
}
catch (HttpException)
{
return;
}
finally
{
outputStream.Close();
}
}
} while (length > 0 && bytesRead > 0)
{
bytesRead = video.Read(buffer, 0, Math.Min(length, buffer.Length));
await outputStream.WriteAsync(buffer, 0, bytesRead);
length -= bytesRead;
} public class VideoController : ApiController
{
[Route("api/video/{ext}/{fileName}")]
public HttpResponseMessage Get(string ext, string fileName)
{
string videoPath = HostingEnvironment.MapPath(string.Format("~/Videos/{0}.{1}", fileName, ext));
if (File.Exists(videoPath))
{
FileInfo fi = new FileInfo(videoPath);
var video = new VideoStream(videoPath);
var response = Request.CreateResponse();
response.Content = new PushStreamContent((Action<Stream, HttpContent, TransportContext>)video.WriteToStream,
new MediaTypeHeaderValue("video/" + ext));
response.Content.Headers.Add("Content-Disposition", "attachment;filename=" + fi.Name.Replace(" ", ""));
response.Content.Headers.Add("Content-Length", video.FileLength.ToString());
return response;
}
else
{
return Request.CreateResponse(HttpStatusCode.NotFound);
}
}
} [Route("api/video/{ext}/{fileName}")] api/video/mp4/sample
string videoPath = HostingEnvironment.MapPath(string.Format("~/Videos/{0}.{1}", fileName, ext)); var video = new VideoStream(videoPath);
var response = Request.CreateResponse();
response.Content = new PushStreamContent((Action<Stream, HttpContent, TransportContext>)video.WriteToStream, new MediaTypeHeaderValue("video/" + ext)); response.Content.Headers.Add("Content-Disposition", "attachment;filename=" + fileName);
response.Content.Headers.Add("Content-Length", video.FileLength.ToString()); if(File.Exists(videoPath))
{
// removed for bravity
}
else
{
return Request.CreateResponse(HttpStatusCode.NotFound);
} public class HomeController : Controller
{
// GET: Home
public ActionResult Index()
{
return View();
}
} <div>
<div>
<video width="480" height="270" controls="controls" preload="auto">
<source src="/api/video/mp4/sample" type="video/mp4" />
Your browser does not support the video tag.
</video>
</div>
</div> قسمت 5ام از سری ویدیو‌های کانکارنسی داریم کم کم به انتهای ویدیو‌ها میرسیم و در این ویدیو درمورد بکگراند ترد‌ها و فرگراند ترد‌ها صحبت کردیم، به طور کامل فضای تسک و ترد پول رو بررسی و باز کردیم و در انتها یه نگاهی هم به فضای async, await انداختیم که در ادامه ویدیو‌ها بیشتر صحبت میکنیم.
0:00 last session
03:00 Background and foreground thread
06:50 CLR
07:19 Thread Pool
11:00 Task
13:30 Task Result
16:40 Long Running Tasks
# Which Approach Should You Use?
We had a look at four different approaches:-Callbacks with the danger of entering callback hell -Promises to escape callback hell-Observables to handle streams of data and apply operator magic -async/ await to write “synchronous” code with promises
// Note: Without this `Include`, HotelRoomImages will be in the detached state and won't be update here.
var actualDbRoom = await _dbContext.HotelRooms.Include(x => x.HotelRoomImages)
.FirstOrDefaultAsync(x => x.Id == roomId); 
IoCWrapper.RunAndDispose(() =>
{
var draftsService = IoCWrapper.GetInstance<IBlogPostDraftsService>();
draftsService.RunConvertDraftsToPostsJob();
}); IoCWrapper.RunAndDispose(async () =>
{
var draftsService = IoCWrapper.GetInstance<IBlogPostDraftsService>();
await draftsService.RunConvertDraftsToPostsJobAsync();
}); System.ObjectDisposedException HResult=0x80131622 Message=The ObjectContext instance has been disposed and can no longer be used for operations that require a connection. Source=EntityFramework
Some key areas of focus uncovered by this investigation were:
Being mindful of memory allocations to minimize GC pause times
Keeping long-running calls non-blocking/asynchronous
Minimizing calls to external resources (such as other web services or the database) with caching and grouping of requests
Silverlight does not enable you to directly enumerate over a data service query. This is because enumeration automatically send a synchronous request to the data service. Because Silverlight only supports asynchronous operations, you must instead call BeginExecute and EndExecute method to obtain a query result that supports enumeration.
