Runnable is a Java interface that defines one method: "run". You can
think of it as a method packaged as an object.
Define a class that implements Runnable, and pass it to m_view.update()
or runOnUIThread().
Once you've done that, the runnable object's run() method will be called
(asynchronously) on the UI thread. This method can then call methods in
m_view to display the message etc.
You might also want to look at AsyncTask:
http://developer.android.com/reference/android/os/AsyncTask.html
>>
AsyncTask enables proper and easy use of the UI thread. This class
allows to perform background operations and publish results on the UI
thread without having to manipulate threads and/or handlers.
<<
-- Kostya
17.10.2010 0:12, chcat пишет:
Ok, that helps, but what is Runnable action and how is it related to
thread?
On Oct 16, 3:00 pm, Kostya Vasilyev<[email protected]> wrote:
You can only access UI objects from the main (UI) thread.
There are several ways to "post" UI operations to the UI thread.
This one is probably the easiest: Activity.runOnUIThread(Runnable action)
http://developer.android.com/reference/android/app/Activity.html#runO...)
-- Kostya
16.10.2010 20:58, chcat пишет:
I have an Activity with TextView that I am trying to update from
different thread. To do that i pass TextView to the "updater" thread
onCreate(..)
..
txtStatus = (TextView)this.findViewById(R.id.status);
// start udp server as separate thread and pass TextView to that
thread to print text messages from udp socket
new Thread(new TelemetryServer(txtStatus)).start();
//see thread code below
As a result i have thread error, even though "updater" is
synchronized:
ERROR/UDP(282): android.view.ViewRoot$CalledFromWrongThreadException:
Only the original thread that created a view hierarchy can touch its
views.
Any other ideas how to solve this problem?
Tnank you,
-V
public class TelemetryServer implements Runnable {
public static final String SERVERIP = "127.0.0.1"; // 'Within' the
emulator!
public static final int SERVERPORT = 2222;
private TextView m_view;
private DatagramSocket socket;
private boolean loop;
private synchronized void update( String msg)
{
m_view.append("\n");
m_view.append(msg);
}
public TelemetryServer(TextView _view)
{
m_view = _view;
loop = true;
}
public void run() {
try {
InetAddress serverAddr =
InetAddress.getByName(SERVERIP);
Log.d("UDP", "S: Connecting...");
socket = new DatagramSocket(SERVERPORT,
serverAddr);
Log.i("TelemetryServer", "started");
while(loop) {
byte[] buf = new byte[1024];
DatagramPacket packet = new
DatagramPacket(buf, buf.length);
socket.receive(packet);
update(new String(packet.getData()));
}
} catch (Exception e) {
Log.e("UDP", "S: Error", e);
} // end of try
Log.d("UDP", "S: Done.");
socket.close();
}
}
--
Kostya Vasilyev -- WiFi Manager + pretty widget --http://kmansoft.wordpress.com
--
Kostya Vasilyev -- WiFi Manager + pretty widget -- http://kmansoft.wordpress.com
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