Ah yes Streets.. that was what I was missing.. been a while since I dealt with UI threads. It's not that you have to run a thread on the UI.. you run a Runnable. The Runnable just defines run() method.. I forget now but I think basically it allows the UI thread to just call run() on your Runnable you pass in to run your UI code.. but it allows you to access the UI thread from outside of that thread (in another thread) so that any UI stuff you need to access or do is possible.. since it will now run on the UI thread. The reason you need to do this is that in a separate thread, and code you use that expects to use the UI in some way, will not be able to access the UI from a different thread. There is quite a bit of code that uses something like Thread.getContextLoader().... and if that call is made while in a separate thread, it will fail if it's expecting to do some UI stuff. When you put that Runnable wraper of your UI code on the UI thread, the UI is available.
On Thu, Jan 21, 2010 at 2:01 PM, Streets Of Boston <[email protected]>wrote: > Note that 'post' and 'runOnUiThread' takes a Runnable and it should > *not* be a Thread (although that implements Runnable as well)! (Mis) > using a Thread for this is not good. Just use a Runnable. > > Create a new instance of a Runnable and implement its 'public void run > ()' method (see my example code in my previous post). > > On Jan 21, 4:50 pm, TreKing <[email protected]> wrote: > > On Thu, Jan 21, 2010 at 3:30 PM, Dirk Vranckaert > > <[email protected]>wrote: > > > > > It seems your solution does not work either. > > > > Um ... it should, I've used this technique repeatedly. Can you post the > code > > you're using? > > > > > As long as I'm doing it in a thread it doesn't work. > > > > Well, it depends on how you're running the thread. If you're posting it > to > > the runOnUiThread() function, it should work. If you're starting it with > > Thread.start(), then yeah, that won't work. Again, some code would > clarify. > > > > > Altough what I tried next was setting the error message for the user > > > in my catch clause. And right after the thread finished I handled the > > > showing of the errors based on wheater some error message was set or > > > not! > > > > I'm not sure I follow here. > > > > > Thx for your help! (If you get me some advanced explanation on why > > > dialogs cannot be created from within a thread plz let me know!) > > > > Probably because of the complexities of ensuring thread safety. If you > could > > update the UI from any thread, you could run into various threading > issues > > (deadlocks, race conditions, etc). If they core framework were designed > to > > support this it would introduce more complexity and overhead to the > system. > > Just a guess, but again, this is pretty standard behavior in GUI systems, > so > > it's really something that's just accepted. > > > > > ------------------------------------------------------------------------------------------------- > > TreKing - Chicago transit tracking app for Android-powered deviceshttp:// > sites.google.com/site/rezmobileapps/treking > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected]<android-developers%[email protected]> > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en > -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
