Tejas, Thanks for very good example. It'll definitely help to setup communication between threads.
It's mean that if we want to communicate from worker thread to main thread then we have to setup one another handler (which is assciated with another message queue) and using same message passing technique (obtainMessage and sendMessage, handleMessage). Conclusion, Handler is one-way message passing technique using queue. - Anurag Singh On Sun, Apr 25, 2010 at 10:08 AM, Tejas <[email protected]> wrote: > So, here is the code to send messages to a worker thread. > In your main thread create a worker thread using HandlerThread: > > HandlerThread myThread = new HandlerThread("Worker > Thread"); > myThread.start(); > > You will have to implement a Handler class for this worker thread. > Suppose it is called MyHandler as follows: > > class MyHandler extends Handler { > public MyHandler(Looper myLooper) { > super(myLooper); > } > public void handleMessage(Message msg) { > Log.v("MyHandler", "handleMessage in worker > thread called"); > } > } > > Now, get the looper from that thread. And pass this looper to the > Handler class you implemented. > Looper mLooper = myThread.getLooper(); > MyHandler mHandler = new MyHandler(mServiceLooper); > > Now from your main thread when you have to pass a message to the > worker thread, do the following: > Message msg = mHandler.obtainMessage(); > //msg.obj = blah blah > mHandler.sendMessage(msg); > > -Cheers, > Tejas > > On Apr 24, 11:58 pm, Tejas <[email protected]> wrote: > > I suppose, to pass data to a worker thread, that thread needs a > > Looper. Hence android has HandlerThread class which creates a looper > > for the worker thread. > > We can get this looper from the worker thread and then send messages > > to it. > > > > Please correct me if I'm wrong. I'll try to find some code > > demonstrating this. If anyone knows it already, please post a sample > > code. > > > > - Tejas > > > > On Apr 24, 11:43 pm, Anurag Singh <[email protected]> wrote: > > > > > > > > > > > > > Dianne, original poster want to pass stuff/data from main thread to > > > secondary thread. > > > > > is it possbile using Handler? Geaneraly, we use Handler to get back > data > > > from secondary thread to main thread using SendMessage() or Post(). > > > > > - Anurag Singh > > > > > > Don't do these things for threads running in the same process (which > is > > > > what the original poster is asking about); much more overhead and > complexity > > > > for no purpose. > > > > > > Handler is Android's standard way to get stuff back on the main > thread. > > > > Create one in the main thread, then post messages or (Runnable > objects if > > > > desired) to get what you want to that thread. > > > > > > The other Java concurrency stuff can be useful, but be careful > because you > > > > don't want to end up with your main thread using that and blocking on > one of > > > > the other threads for data from it. The main thread is > message-based, so > > > > posting messages to it via Handler is a good approach. > > > > > > -- > > > > Dianne Hackborn > > > > Android framework engineer > > > > [email protected] > > > > > > Note: please don't send private questions to me, as I don't have time > to > > > > provide private support, and so won't reply to such e-mails. All > such > > > > questions should be posted on public forums, where I and others can > see and > > > > answer them. > > > > > > -- > > > > 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]><android-developers%2Bunsubs > [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]<android-developers%[email protected]> > > > For more options, visit this group athttp:// > 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]<android-developers%[email protected]> > > For more options, visit this group athttp:// > 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]<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. 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