Hello!
Iam looking for some advice in matter of multithreaded operations on UltraDataSource (IG7.1.20071.40). As I was writing in my some other post Iam constructing Explorer like test-app with IG. I have UltraDataSource binded to the UltraGrid. Already stumbled on the "red cross error" and Iam aware that modyfing data on external thread is reason of it. Ive read probably everyting on threading and IG avalible on forums, but still can't apply my knowledge against UltraDataSource component.
App works like this (1 thread only):(1) UltraGrid binded with UltraSource with basic Band(2) App start. App lists C: dir(3) If app founds not empty dir it creates an empty childband for it with a "dummy-row" so the [+] would appear.(4) If user clicks on [+] which was placed for the "dummy" row, app responds on it in "BeforeExpand" event(5) App fetches the subdirstructure and applies it to the childband (removing dummy-row first), and then expands and show structure...While its only on one thread it "frozes" while fetching structure of large dir. I wanted to put step (5) in another thread and "update live" the expanded node view. But is it even possible with UltraDataSource ?
Ive found the UI Thread Marshaling in the Model Layer article, but example presented there applies to CutomDataSet which inherits from DataSet class, and it "binds" together in this point of code: this.Tables.Add(MainTable)
Ive tried to implement it for UltraDataSource but failed miserably. Is above example event applies to the Model-Views solution ? Please help
Hi,
Sorry, but I really don't have any experience with this sort of thing, so I don't have anything constructive to tell you. I was hoping someone else out there who had done this might reply and help you out.
I'm not even really sure what you are asking. Short of actually writing the code to do this, I'm not sure what help anyone could offer you here, since this is a pretty complex issue with lot of potential pitfalls.
Above irony wasn't "pointed" at you Mike. Youre doing a great job in helping ppl at the forum, but as long as its a forum, I was also hoping that someone from "forumers" haved same problem, but I was mistaken.
Anyway project for now is on hold, due to its singlethreading. Meaby I will come up with some solution in future, but for now Iam out of time to work @ this stuff.
Main subject of the problem is that is it possible to modify UltraDataSource which is connected directly to UltraWinGrid in Win32 enviroment in separate thread(s). Probably yes, by "aproprieate marshaling of code", but I haven figure out what that would mean relating to the UltraDataSource. yet!
Best regards
Sounds very tricky to me. Using multiple threads in general is much trickier than a lot of people realize. It's very easy to do something on one thread that affects someting on the UI thread unintentionally. And these things are very difficult to track down.