Lwuit与Lcdui可以相互调用，如果需要在一个Midlet中同时使用Lwuit和Lcdui库，需要在Midlet中保留一个Lcdui Display的全局变量，可以在startApp方法中初始化。示例如下：
private javax.microedition.lcdui.Display lcduiDisplay; //.... public void startMIDlet() { //... lcduiDisplay = Display.getDisplay( this ); //... } 如果是从Lwuit切换到Lcdui，通过使用Lcdui Display的setCurrent方法，示例如下： lcduiDisplay.setCurrent(lcduiForm); 如果是从Lcdui切换到Lwuit，先初始化Lwuit Display，然后调用Component的show方法，示例如下： com.sun.lwuit.Display.init( this ); com.sun.lwuit.Form lwuitForm = new com.sun.lwuit.Form( "LWUIT FORM" ); //... lwuitForm.show();附源代码：
/* * To change this template, choose Tools | Templates * and open the template in the editor. */ package DemoLwuitLcdui; import com.sun.lwuit.events.ActionEvent; import javax.microedition.midlet.*; import javax.microedition.lcdui.*; /** * @author Administrator */ public class DemoLwuitLcduiMIDlet extends MIDlet implements CommandListener { private boolean midletPaused = false; //<editor-fold defaultstate="collapsed" desc=" Generated Fields ">//GEN-BEGIN:|fields|0| private Command exitCommand; private Command switchToLwuitFormCommand; private Form lcduiForm; private StringItem stringItem; //</editor-fold>//GEN-END:|fields|0| private com.sun.lwuit.Display lwuitDisplay; private javax.microedition.lcdui.Display lcduiDisplay; /** * The DemoLwuitLcduiMIDlet constructor. */ public DemoLwuitLcduiMIDlet() { } //<editor-fold defaultstate="collapsed" desc=" Generated Methods ">//GEN-BEGIN:|methods|0| //</editor-fold>//GEN-END:|methods|0| //<editor-fold defaultstate="collapsed" desc=" Generated Method: initialize ">//GEN-BEGIN:|0-initialize|0|0-preInitialize /** * Initilizes the application. * It is called only once when the MIDlet is started. The method is called before the <code>startMIDlet</code> method. */ private void initialize() {//GEN-END:|0-initialize|0|0-preInitialize // write pre-initialize user code here //GEN-LINE:|0-initialize|1|0-postInitialize // write post-initialize user code here }//GEN-BEGIN:|0-initialize|2| //</editor-fold>//GEN-END:|0-initialize|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: startMIDlet ">//GEN-BEGIN:|3-startMIDlet|0|3-preAction /** * Performs an action assigned to the Mobile Device - MIDlet Started point. */ public void startMIDlet() {//GEN-END:|3-startMIDlet|0|3-preAction // write pre-action user code here switchDisplayable(null, getLcduiForm());//GEN-LINE:|3-startMIDlet|1|3-postAction //lwuitDisplay = com.sun.lwuit.Display.getInstance(); lcduiDisplay = Display.getDisplay(this); // write post-action user code here }//GEN-BEGIN:|3-startMIDlet|2| //</editor-fold>//GEN-END:|3-startMIDlet|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: resumeMIDlet ">//GEN-BEGIN:|4-resumeMIDlet|0|4-preAction /** * Performs an action assigned to the Mobile Device - MIDlet Resumed point. */ public void resumeMIDlet() {//GEN-END:|4-resumeMIDlet|0|4-preAction // write pre-action user code here //GEN-LINE:|4-resumeMIDlet|1|4-postAction // write post-action user code here }//GEN-BEGIN:|4-resumeMIDlet|2| //</editor-fold>//GEN-END:|4-resumeMIDlet|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: switchDisplayable ">//GEN-BEGIN:|5-switchDisplayable|0|5-preSwitch /** * Switches a current displayable in a display. The <code>display</code> instance is taken from <code>getDisplay</code> method. This method is used by all actions in the design for switching displayable. * @param alert the Alert which is temporarily set to the display; if <code>null</code>, then <code>nextDisplayable</code> is set immediately * @param nextDisplayable the Displayable to be set */ public void switchDisplayable(Alert alert, Displayable nextDisplayable) {//GEN-END:|5-switchDisplayable|0|5-preSwitch // write pre-switch user code here Display display = getDisplay();//GEN-BEGIN:|5-switchDisplayable|1|5-postSwitch if (alert == null) { display.setCurrent(nextDisplayable); } else { display.setCurrent(alert, nextDisplayable); }//GEN-END:|5-switchDisplayable|1|5-postSwitch // write post-switch user code here }//GEN-BEGIN:|5-switchDisplayable|2| //</editor-fold>//GEN-END:|5-switchDisplayable|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Displayables ">//GEN-BEGIN:|7-commandAction|0|7-preCommandAction /** * Called by a system to indicated that a command has been invoked on a particular displayable. * @param command the Command that was invoked * @param displayable the Displayable where the command was invoked */ public void commandAction(Command command, Displayable displayable) {//GEN-END:|7-commandAction|0|7-preCommandAction // write pre-action user code here if (displayable == lcduiForm) {//GEN-BEGIN:|7-commandAction|1|19-preAction if (command == exitCommand) {//GEN-END:|7-commandAction|1|19-preAction // write pre-action user code here exitMIDlet();//GEN-LINE:|7-commandAction|2|19-postAction // write post-action user code here } else if (command == switchToLwuitFormCommand) {//GEN-LINE:|7-commandAction|3|23-preAction // write pre-action user code here com.sun.lwuit.Display.init(this); com.sun.lwuit.Form lwuitForm = new com.sun.lwuit.Form("LWUIT FORM"); lwuitForm.addComponent(new com.sun.lwuit.Label("Thi is a Lwuit Form.")); lwuitForm.addComponent(new com.sun.lwuit.Label("Press Lcdui Form Command to ")); lwuitForm.addComponent(new com.sun.lwuit.Label("switch to Lcdui Form.")); com.sun.lwuit.Command switchToLcduiFormCommand = new com.sun.lwuit.Command("Lcdui Form"); lwuitForm.addCommand(switchToLcduiFormCommand); lwuitForm.addCommandListener(new com.sun.lwuit.events.ActionListener() { public void actionPerformed(ActionEvent ae) { if (ae.getCommand().getCommandName().equals("Lcdui Form")) { lcduiDisplay.setCurrent(lcduiForm); } } }); lwuitForm.show(); //GEN-LINE:|7-commandAction|4|23-postAction // write post-action user code here }//GEN-BEGIN:|7-commandAction|5|7-postCommandAction }//GEN-END:|7-commandAction|5|7-postCommandAction // write post-action user code here }//GEN-BEGIN:|7-commandAction|6| //</editor-fold>//GEN-END:|7-commandAction|6| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: exitCommand ">//GEN-BEGIN:|18-getter|0|18-preInit /** * Returns an initiliazed instance of exitCommand component. * @return the initialized component instance */ public Command getExitCommand() { if (exitCommand == null) {//GEN-END:|18-getter|0|18-preInit // write pre-init user code here exitCommand = new Command("Exit", Command.EXIT, 0);//GEN-LINE:|18-getter|1|18-postInit // write post-init user code here }//GEN-BEGIN:|18-getter|2| return exitCommand; } //</editor-fold>//GEN-END:|18-getter|2| //</editor-fold> //<editor-fold defaultstate="collapsed" desc=" Generated Getter: lcduiForm ">//GEN-BEGIN:|14-getter|0|14-preInit /** * Returns an initiliazed instance of lcduiForm component. * @return the initialized component instance */ public Form getLcduiForm() { if (lcduiForm == null) {//GEN-END:|14-getter|0|14-preInit // write pre-init user code here lcduiForm = new Form("LCDUI Form", new Item[] { getStringItem() });//GEN-BEGIN:|14-getter|1|14-postInit lcduiForm.addCommand(getExitCommand()); lcduiForm.addCommand(getSwitchToLwuitFormCommand()); lcduiForm.setCommandListener(this);//GEN-END:|14-getter|1|14-postInit // write post-init user code here }//GEN-BEGIN:|14-getter|2| return lcduiForm; } //</editor-fold>//GEN-END:|14-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: stringItem ">//GEN-BEGIN:|16-getter|0|16-preInit /** * Returns an initiliazed instance of stringItem component. * @return the initialized component instance */ public StringItem getStringItem() { if (stringItem == null) {//GEN-END:|16-getter|0|16-preInit // write pre-init user code here stringItem = new StringItem("This is a Lcdui Form", "Press Lwuit Form Command to switch to lwuit form");//GEN-LINE:|16-getter|1|16-postInit // write post-init user code here }//GEN-BEGIN:|16-getter|2| return stringItem; } //</editor-fold>//GEN-END:|16-getter|2| //</editor-fold> //<editor-fold defaultstate="collapsed" desc=" Generated Getter: switchToLwuitFormCommand ">//GEN-BEGIN:|22-getter|0|22-preInit /** * Returns an initiliazed instance of switchToLwuitFormCommand component. * @return the initialized component instance */ public Command getSwitchToLwuitFormCommand() { if (switchToLwuitFormCommand == null) {//GEN-END:|22-getter|0|22-preInit // write pre-init user code here switchToLwuitFormCommand = new Command("LwuitForm", Command.OK, 0);//GEN-LINE:|22-getter|1|22-postInit // write post-init user code here }//GEN-BEGIN:|22-getter|2| return switchToLwuitFormCommand; } //</editor-fold>//GEN-END:|22-getter|2| /** * Returns a display instance. * @return the display instance. */ public Display getDisplay () { return Display.getDisplay(this); } /** * Exits MIDlet. */ public void exitMIDlet() { switchDisplayable (null, null); destroyApp(true); notifyDestroyed(); } /** * Called when MIDlet is started. * Checks whether the MIDlet have been already started and initialize/starts or resumes the MIDlet. */ public void startApp() { if (midletPaused) { resumeMIDlet (); } else { initialize (); startMIDlet (); } midletPaused = false; } /** * Called when MIDlet is paused. */ public void pauseApp() { midletPaused = true; } /** * Called to signal the MIDlet to terminate. * @param unconditional if true, then the MIDlet has to be unconditionally terminated and all resources has to be released. */ public void destroyApp( boolean unconditional) { }}
