Blackberry - LabelField Dynamic Update Issues

Question

I am trying to develop a BlackBerry app for a Storm2. I am facing a problem when trying to update a LabelField from a different instance of the app.

The program is working fine without updating this LabelField, but when I tried to add the code to update the text, it becomes unresponsive after the "settext" line.

Am I missing something?

public class AgentTrackerScreen extends MainScreen
{
    public static LabelField _outputText;
    ...
}

public class BtService implements Runnable
{
    ...
    public void run() 
    {
        AgentTrackerScreen._outputtext.settext(
            "Something: " + btListener.vecDevices.size());
    }
    ...
}

Try splitting the code inside your `run()` method into two lines (first line creates the string and second line uses the string in `settext`) to see whether the problem is with `settext` or with `btListener.vecDevices.size()`. — MusiGenesis, Feb 08 '11 at 15:34
I have already tried that. btListener.vecDevices.size() is working fine; I think settext is the one that have issues. — RA Student, Feb 08 '11 at 15:43

score 3 · Answer 1 · edited Jun 29 '11 at 10:37

3

You must make all user interface modifications on the event thread, or else lock the user interface before doing it. See BlackBerry UI Threading Basics for details.

(BTW, this is a common requirement in many user interface systems. Swing in Java SE has this requirement. So does WPF on Windows.)

edited Jun 29 '11 at 10:37

Dhruv

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answered Feb 08 '11 at 16:06

Eric Giguere

3,495
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score 1 · Answer 2 · answered Feb 09 '11 at 13:44

1

Use either:

invokeAndWait(Runnable r)
invokeLater(Runnable r)
synchronize on UiApplication.getEventLock()

answered Feb 09 '11 at 13:44

Todd

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Blackberry - LabelField Dynamic Update Issues

2 Answers2

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