listdemo.java

J2ME开发实例J2ME开发实例J2ME开发实例J2ME开发实例J2ME开发实例

package trainning.list;

import javax.microedition.lcdui.Choice;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.List;
import javax.microedition.midlet.*;

public class ListDemo extends MIDlet implements CommandListener {

    private final static Command CMD_EXIT = new Command("Exit", Command.EXIT, 1);
    private final static Command CMD_BACK = new Command("Back", Command.BACK, 1);
    private Display display;
    private List mainList;
    private List exclusiveList;
    private List implicitList;
    private List multipleList;

    private boolean firstTime;

    public ListDemo() {

        display = Display.getDisplay(this);

        String[] stringArray = {
            "Option A",
            "Option B",
            "Option C",
            "Option D"
        };
        Image[] imageArray = null;
        
        exclusiveList = new List("Exclusive", List.EXCLUSIVE, stringArray, imageArray);
        exclusiveList.addCommand(CMD_BACK);
        exclusiveList.addCommand(CMD_EXIT);
        exclusiveList.setCommandListener(this);

        implicitList = new List("Implicit", List.IMPLICIT, stringArray, imageArray);
        implicitList.addCommand(CMD_BACK);
        implicitList.addCommand(CMD_EXIT);
        implicitList.setCommandListener(this);

        multipleList = new List("Multiple", List.MULTIPLE, stringArray, imageArray);
        multipleList.addCommand(CMD_BACK);
        multipleList.addCommand(CMD_EXIT);
        multipleList.setCommandListener(this);

        firstTime = true;
    }

    public void startApp() {

        if(firstTime) {
            Image[] imageArray = null;
            try {
                Image icon = null;
                imageArray = new Image[] {
                    icon,
                    icon,
                    icon
                };
            }
            catch(Exception e) {
                e.printStackTrace();
            }

            String[] stringArray = new String[] {
                "Exclusive",
                "Implicit",
                "Multiple"
            };

            mainList = new List("Choose type", Choice.IMPLICIT, stringArray, imageArray);
            mainList.addCommand(CMD_EXIT);
            mainList.setCommandListener(this);

            display.setCurrent(mainList);
            firstTime = false;
        }
    }

    public void pauseApp() {
    }

    public void destroyApp(boolean unconditional) {
    }

    public void commandAction(Command c, Displayable d) {

        if(d.equals(mainList)) {
            if(c == List.SELECT_COMMAND) {
                if(d.equals(mainList)) {
                    switch(((List)d).getSelectedIndex()) {
                        case 0:
                            display.setCurrent(exclusiveList);
                            break;
                        case 1:
                            display.setCurrent(implicitList);
                            break;
                        case 2:
                            display.setCurrent(multipleList);
                            break;
                    }
                }
            }
            else {
                if(c == CMD_BACK) {
                    display.setCurrent(mainList);
                }
            }

            if(c == CMD_EXIT) {
                destroyApp(false);
                notifyDestroyed();
            }
        }
    }
}