C# - How to get synchronous UI update from the InvokeRequired pattern?
I have a number of threads to append text to a rich text box. With Invoke(), I very easily get deadlock between the mai开发者_JS百科n UI thread and the worker threads. With BeginInvoke(), I get async UI update, which I do not want. I want the texts appear in the text box instantly, not at some later stage that I can't determine.
How do I do my task?
Thanks!
You cannot magically run on the UI thread without touching the UI thread.
If you want to call Invoke
, you need to make the UI thread stop waiting for the background threads.
However, you should just call BeginInvoke
instead.
BeginInvoke
isn't any less instant than Invoke
; the only difference is that Invoke
forces the calling thread to wait until the UI thread has a chance to run the delegate.
You would call Invoke
if the background thread needs to wait for the UI thread to run the delegate (eg, if it returns a value).
In normal cases, you should always call BeginInvoke
; there's usually no point in making the background thread wait until the UI thread is free.
精彩评论