You probably don’t want to call Task.Result, for a couple of reasons. Firstly, as I explain in detail on my blog, you can deadlock unless your async code is has been written using ConfigureAwait everywhere. Secondly, you probably don’t want to (synchronously) block your UI; it would be better to temporarily show a “loading…” or … Read more
MSDN explains everything. I understand though that sometimes vanilla docs (particularly from MSDN) can be difficult to apply to your particular situation, so let’s go over your points. Question # 1: Is this assumption correct or the code below the await keyword is still executed? The code below the “await” keyword will only be executed … Read more
Your code is short, readable and efficient, so I don’t understand why are you looking for alternatives, but I can’t think of anything. I think your approach is reasonable. I’m also not sure why do you think that the synchronous part is okay in the original version, but you want to avoid it in the … Read more
What you are describing can be accomplished with the Task.WhenAll method. Notice how the code turns into a simple one-liner. What happens is that each individual url begins downloading and then WhenAll is used combine those operations into a single Task which can be awaited. Task<IEnumerable<string>> DownLoadAllUrls(string[] urls) { return Task.WhenAll(from url in urls select … Read more
Does an implicit conversion occur between Task<> and int? Nope. This is just part of how async/await works. Any method declared as async has to have a return type of: void (avoid if possible) Task (no result beyond notification of completion/failure) Task<T> (for a logical result of type T in an async manner) The compiler … Read more
You have the “Just my code” Option turned on. With this on, it is considering the exception unhandled with respect to “just your code”–because other code is catching the exception and stuffing it inside of a Task, later to be rethrown at the await call and caught by your catch statement. Without being attached in … Read more
I think that maybe you misunderstand what async does. The warning is exactly right: if you mark your method async but don’t use await anywhere, then your method won’t be asynchronous. If you call it, all the code inside the method will execute synchronously. Also, you should try to avoid using async void methods, they … Read more
This is a change to the C# language, not the .NET framework. Therefore, it only affects code compiled under C# 5.0, regardless of the .NET framework version on which that code will execute. C# 5.0 Section 8.8.4 of the specification makes it clear that this change has been made. Specifically, page 249 of the C# … Read more
They just talked about this at PDC yesterday! Await is used in conjunction with Tasks (parallel programming) in .NET. It’s a keyword being introduced in the next version of .NET. It more or less lets you “pause” the execution of a method to wait for the Task to complete execution. Here’s a brief example: //create … Read more
I disagree with the implication in your question title that await‘s behavior is undesired. It makes sense in the vast majority of scenarios. In a WhenAll situation, how often do you really need to know all of the error details, as opposed to just one? The main difficulty with AggregateException is the exception handling, i.e., … Read more