MultiThreaded stuff.

[psycik]

Hi

Trying to make my music player a bit better. Loading playlists were a place where the UI would stop while a large playlist was loaded. So I'd like to make it load in background.

I've managed to make it start a new thread to load the playlist files inthe background ok. But the problem comes when trying to play them.

If I try to play a track while it loading, and call a PluginHelperFactory.AddAudioFileToQueue() both within the playlist class (that's currently loading - i.e. so in the new thread) or an event that fires when each track is loaded I get

Code:

Cross-thread operation not valid: Control 'HomeMenu' accessed from a thread other than the thread it was created on.

Any pointers to how I should be doing this?? I'm pretty new to multi-threading...

[sub]

This can be tricky. There are several of the PluginHelper APIs that can only be called on the main thread - primarily any that need to tell a music file to start playing. This is because this is a limitation of the Windows Media Player control. You would have got away with calling AddAudioFileToQueue() if a music file had already been playing (initiated from main thread).

In general I use background threads for doing long running activities (downloading youtube files etc), but only call the playback APIs from the main thread if I see semaphore/flag indicating the download is complete.

[psycik]

I've managed to make it start playing a first track, and I'll just figure out a way of notifiying the rest of the program that the remainder of the tracks are ready.

[sub]

As long as it's already playing, you'd be safe to call the AddAudioFileToQueue() method in the background thread. Its probably the easiest way to achieve what you want.

[psycik]

oh ok, something to try then. I'll let you know.

Have to see what other things I can push into a background thread.