(CSDN June 14, 2006)
.NET threading is not quite hard, if you only use a few threads. For example, two or three threads are used in InDate (in Integrated mode three threads, standalone mode two).
In order to make the textbox unlocked when updating, I saw to SDK document and found a DirectorySearcher sample.
It is amazing that this sample tells just what I need. And I know a little about Control class by the way. After reading and modifying the source, I turn my Updater.cs into a user control and slightly edit FormInDate. Then it goes just fine.
I think only two threads are needed when integrated mode is set. I will see to that soon.