怎么样做一个tabscreen

就是屏幕上方带有标签可以切换的屏幕，转官方的代码。

 

package com.rim.samples.tabcontrol;

import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.FocusChangeListener;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.component.BasicEditField;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.SeparatorField;
import net.rim.device.api.ui.container.HorizontalFieldManager;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;

public class TabControl extends UiApplication {

        public TabControl() {
                TabControlScreen screen = new TabControlScreen();
                pushScreen(screen);
        }

        /**
         * @param args
         */
        public static void main(String[] args) {
                TabControl app = new TabControl();
                app.enterEventDispatcher();
        }

        private class TabControlScreen extends MainScreen implements FocusChangeListener {

                private LabelField tab1;

                private LabelField tab2;

                private LabelField tab3;

                private LabelField spacer1;

                private LabelField spacer2;

                private VerticalFieldManager tabArea;

                private LabelField tab1Heading;

                private BasicEditField tab1Field1;

                private BasicEditField tab1Field2;

                private LabelField tab2Heading;

                private BasicEditField tab2Field1;

                private BasicEditField tab2Field2;

                private LabelField tab3Heading;

                private BasicEditField tab3Field1;

                private BasicEditField tab3Field2;
               
                private VerticalFieldManager tab1Manager;
                private VerticalFieldManager tab2Manager;
                private VerticalFieldManager tab3Manager;
               

                public TabControlScreen() {
                        HorizontalFieldManager hManager = new HorizontalFieldManager();
                        tab1 = new LabelField("Page 1", LabelField.FOCUSABLE);
                        tab2 = new LabelField("Page 2", LabelField.FOCUSABLE);
                        tab3 = new LabelField("Page 3", LabelField.FOCUSABLE);
                        spacer1 = new LabelField(" | ", LabelField.NON_FOCUSABLE);
                        spacer2 = new LabelField(" | ", LabelField.NON_FOCUSABLE);

                        tab1.setFocusListener(this);
                        tab2.setFocusListener(this);
                        tab3.setFocusListener(this);
                        hManager.add(tab1);
                        hManager.add(spacer1);
                        hManager.add(tab2);
                        hManager.add(spacer2);
                        hManager.add(tab3);

                        add(hManager);
                        add(new SeparatorField());
                       
                        tab1Manager = new VerticalFieldManager();
                        tab2Manager = new VerticalFieldManager();
                        tab3Manager = new VerticalFieldManager();

                        tabArea = displayTab1();
                        add(tabArea);

                }

                public void focusChanged(Field field, int eventType) {
                        if (tabArea != null) {
                                if (eventType == FOCUS_GAINED) {
                                        if (field == tab1) {
                                                System.out.println("Switch to Tab 1");
                                                delete(tabArea);
                                                tabArea = displayTab1();
                                                add(tabArea);
                                        } else if (field == tab2) {
                                                System.out.println("Switch to Tab 2");
                                                System.out.println("Switch to Tab 1");
                                                delete(tabArea);
                                                tabArea = displayTab2();
                                                add(tabArea);
                                        } else if (field == tab3) {
                                                System.out.println("Switch to Tab 3");
                                                System.out.println("Switch to Tab 1");
                                                delete(tabArea);
                                                tabArea = displayTab3();
                                                add(tabArea);
                                        }
                                }
                        }

                }

                public VerticalFieldManager displayTab1() {
                        if (tab1Heading == null) {
                                tab1Heading = new LabelField("Registration");
                                tab1Manager.add(tab1Heading);
                        }
                        if (tab1Field1 == null) {
                                tab1Field1 = new BasicEditField("Username: ", "");
                                tab1Manager.add(tab1Field1);
                        }
                        if (tab1Field2 == null) {
                                tab1Field2 = new BasicEditField("Password: ", "");
                                tab1Manager.add(tab1Field2);
                        }
                        return tab1Manager;
                }

                public VerticalFieldManager displayTab2() {
                        if (tab2Heading == null) {
                                tab2Heading = new LabelField("Password Recovery");
                                tab2Manager.add(tab2Heading);
                        }
                        if (tab2Field1 == null) {
                                tab2Field1 = new BasicEditField("Security Question: ", "Mother's Maiden Name?");
                                tab2Manager.add(tab2Field1);
                        }
                        if (tab2Field2 == null) {
                                tab2Field2 = new BasicEditField("Password: ", "");
                                tab2Manager.add(tab2Field2);
                        }
                        return tab2Manager;
                }

                public VerticalFieldManager displayTab3() {
                        if (tab3Heading == null) {
                                tab3Heading = new LabelField("Interests");
                                tab3Manager.add(tab3Heading);
                        }
                        if (tab3Field1 == null) {
                                tab3Field1 = new BasicEditField("Hobbies: ", "");
                                tab3Manager.add(tab3Field1);
                        }
                        if (tab3Field2 == null) {
                                tab3Field2 = new BasicEditField("Memberships: ", "");
                                tab3Manager.add(tab3Field2);
                        }
                        return tab3Manager;
                }

        }

}