看看RIM 的这个 BlackBerry 示例。它有点旧,但如果您仍然必须支持 OS 5.0,这是一种有用的技术(如果您不支持 OS 5.0,请参阅答案底部)。
从描述:
基本方法是使用一组管理器来控制在选择选项卡时出现在屏幕上的字段集。选项卡被实现为可聚焦的标签字段,当焦点发生变化时,FocusChangeListener 会执行管理器切换。字段和管理器被初始化一次并保存在内存中以保留选项卡之间的状态变化。
该页面有示例代码可供下载,但为了防止任何可能的链接失效,这里是示例中最重要的部分:
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;
}
}
}
你说:
我想为不同的选项卡创建不同的 java 类。
在您的代码中,您可以编辑名为displayTab1()
、displayTab2()
等的方法,以便为每个选项卡返回不同的类。完全按照示例,每个类都extend
将VerticalFieldManager
类。但是,如果您想要的实现没有很好地设置 a VerticalFieldManager
,您当然可以将这些方法的返回值更改为只是Manager
基类。
如果您这样做,请记住更改tabArea
成员变量:
private Manager tabArea;
注意:如果您只需要支持 OS 6.0 及更高版本,您还可以查看这个较新的 API