问题
Can anyone point me to some patterns for handling async workflows in C#? I know this is coming soon in C# 5 but I was wondering if anyone had already done an implementation in C# 4 that approximates the same effects?
Basically I'm writing a lot of async code in Silverlight 4 like this:
CallService(
(service) => service.DoSomething(1, 2, 3),
(response) =>
{
// some local code
// need to call another service async
CallService(
(service) => service.DoSomethingElse(4, 5, 6),
(response) =>
{
// even more nested async calls, you get the idea...
}
)
}
);
The nested callbacks are getting to me. I really like the way F# provides async workflows to handle this, as you end up writing code that looks and feels synchronous, which is what I really want.
回答1:
We have implemented an async library based on the following set of articles:
http://www.codeproject.com/KB/silverlight/ConsumingWCFServiceWithou.aspx http://www.codeproject.com/KB/silverlight/FixingAllAsync.aspx
Pay particular attention to Part 2 of the article which describes how to simplify async WCF service calls. The author describes an approach to the consumption of asynchronous services based on coroutines. A fantastic article.
回答2:
You can try to use Caliburn Micro framework, which is MVVM framework, but it also provides an implementation for coroutines - it allows you to invoke async methods in a sequence way.
In general I highly recommend you reading about whole Caliburn Micro framework.
You can also read more about coroutines on Matt Hamilton blog
回答3:
Have you had a look at Reactive Extensions?
Works on SL and .NET and provides some really nice ways of having async code
http://msdn.microsoft.com/en-us/data/gg577609
Alternatively maybe look at F# which already has async in Silverlight 4. Heres a (cheeky) look....
http://www.trelford.com/blog/post/Exclusive-New-C-5-features-available-in-VS2010-SP1.aspx
回答4:
Jeremy Likness has a nice series of blog posts where he describes using iterators to process sequential asynchronous calls:
Part 1: Sequential Asynchronous Workflows in Silverlight using Coroutines
Part 2: Sequential Asynchronous Workflows Part 2: Simplified
来源:https://stackoverflow.com/questions/6529066/any-good-async-workflow-patterns-for-c-sharp-4