How to cancel an asynchronous call? 异步调用 的中断 取消 c#

A "cancel flag" is the way to do it, though not a global one, necessarily. The unavoidable point is that you needsome way to signal to the thread that it should stop what it's doing.

In the case of

BeginInvoke

, this is hard to do with anything but a global flag, because the work is carried out on the threadpool, and you don't know which thread. You have a couple of options (in order of preference):

Use the

BackgroundWorker

instead of

BeginInvoke

. This hascancellation functionality baked-in.
This has other benefits, like
progress monitoring, and
"Work complete" callbacks. It also nicely
handles exceptions.
Use

ThreadPool.QueueUserWorkItem

, passing in an object as the state that has a

Cancel()

method that sets a

Cancelled

flag that the executing code can check. Of course you'll need to keep a reference to the state object so you can call

Cancel()

on it (which is something the

BackgroundWorker

does for you - you have a component on your form. (Thanks toFredrik for reminding about this).
Create your own

ThreadStart

delegate, passing in a state object as with option 2.

详见：http://stackoverflow.com/questions/1729346/how-to-cancel-an-asynchronous-call