blackberry java wait screen (ActivityIndicatorView)

how to add a activity screen 开发者_如何学Cto a button click event ?

            ActivityIndicatorView view = new ActivityIndicatorView(Field.FIELD_HCENTER);
        Bitmap spinImage = Bitmap.getBitmapResource("spinner.png");
        view.createActivityImageField(spinImage,6,0);
        LabelField label = new LabelField("Loading Hockey...");
        s.add(label);
        s.add(view);
        pushScreen(s);

by this code, it will shows error. ie no import package how to solve this ?

Are you importing all the right packages? i.e.

import net.rim.device.api.ui.component.progressindicator.*;
import net.rim.device.api.ui.*;

and so on....