Android: passing arguments to threads

Question

How can I pass the context and the name string as arguments to the new thread?

Errors in compilation:

Line

label = new TextView(this);

The constructor TextView(new Runnable(){}) is undefined

Line " label.setText(name); " :

Cannot refer to a non-final variable name inside an inner class defined in a different method

Code:

public void addObjectLabel (String name) {
    mLayout.post(new Runnable() {
        public void run() {
            TextView label;
            label = new TextView(this);
            label.setText(name);
            label.setWidth(label.getWidth()+100);
            label.setTextSize(20);
            label.setGravity(Gravity.BOTTOM);
            label.setBackgroundColor(Color.BLACK);
            panel.addView(label);
        }
    });
}

Answer 1

You need to declare name as final , otherwise you can't use it in an inner anonymous class .

Additionally, you need to declare which this you want to use; as it stands, you're using the Runnable object's this reference. What you need is something like this:

public class YourClassName extends Activity { // The name of your class would obviously be here; and I assume it's an Activity
    public void addObjectLabel(final String name) { // This is where we declare "name" to be final
        mLayout.post(new Runnable() {
            public void run() {
                TextView label;
                label = new TextView(YourClassName.this); // This is the name of your class above
                label.setText(name);
                label.setWidth(label.getWidth()+100);
                label.setTextSize(20);
                label.setGravity(Gravity.BOTTOM);
                label.setBackgroundColor(Color.BLACK);
                panel.addView(label);
            }
        });
    }
}

However, I'm not sure this is the best way to update the UI (you should probably be using runOnUiThread and AsyncTask ). But the above should fix the errors you've encountered.